diff --git a/java/pom.xml b/java/pom.xml
index 0fa2200..405ce93 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -1,403 +1,403 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
 
   <groupId>org.softwareheritage.graph</groupId>
   <artifactId>swh-graph</artifactId>
   <version>${git.closest.tag.name}</version>
 
   <name>swh-graph</name>
   <url>https://forge.softwareheritage.org/source/swh-graph/</url>
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <maven.compiler.release>11</maven.compiler.release>
       <protobuf.version>3.21.1</protobuf.version>
       <grpc.version>1.47.0</grpc.version>
   </properties>
 
   <dependencies>
     <dependency>
       <groupId>ch.qos.logback</groupId>
       <artifactId>logback-classic</artifactId>
       <version>1.2.3</version>
     </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-api</artifactId>
       <version>5.7.0</version>
       <scope>test</scope>
     </dependency>
     <dependency>
         <groupId>org.junit.jupiter</groupId>
         <artifactId>junit-jupiter-engine</artifactId>
         <version>5.7.0</version>
         <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-simple</artifactId>
       <version>1.7.26</version>
     </dependency>
     <dependency>
       <groupId>it.unimi.dsi</groupId>
       <artifactId>webgraph-big</artifactId>
-      <version>3.6.7</version>
+      <version>3.7.0</version>
     </dependency>
     <dependency>
       <groupId>it.unimi.dsi</groupId>
       <artifactId>fastutil</artifactId>
       <version>8.5.8</version>
     </dependency>
     <dependency>
       <groupId>it.unimi.dsi</groupId>
       <artifactId>dsiutils</artifactId>
-      <version>2.7.1</version>
+      <version>2.7.2</version>
     </dependency>
     <dependency>
         <groupId>it.unimi.dsi</groupId>
         <artifactId>sux4j</artifactId>
         <version>5.3.1</version>
     </dependency>
     <dependency>
       <groupId>it.unimi.dsi</groupId>
       <artifactId>law</artifactId>
       <version>2.7.2</version>
       <exclusions>
         <exclusion>
           <groupId>org.apache.hadoop</groupId>
           <artifactId>hadoop-common</artifactId>
         </exclusion>
         <exclusion>
           <groupId>org.umlgraph</groupId>
           <artifactId>umlgraph</artifactId>
         </exclusion>
         <exclusion>
           <groupId>org.eclipse.jetty.aggregate</groupId>
           <artifactId>jetty-all</artifactId>
         </exclusion>
         <exclusion>
           <groupId>it.unimi.di</groupId>
           <artifactId>mg4j</artifactId>
         </exclusion>
         <exclusion>
           <groupId>it.unimi.di</groupId>
           <artifactId>mg4j-big</artifactId>
         </exclusion>
       </exclusions>
     </dependency>
     <dependency>
       <groupId>com.martiansoftware</groupId>
       <artifactId>jsap</artifactId>
       <version>2.1</version>
     </dependency>
     <dependency>
       <groupId>commons-codec</groupId>
       <artifactId>commons-codec</artifactId>
       <version>1.15</version>
     </dependency>
     <dependency>
       <groupId>com.github.luben</groupId>
       <artifactId>zstd-jni</artifactId>
       <version>1.5.1-1</version>
     </dependency>
     <dependency>
       <groupId>org.apache.orc</groupId>
       <artifactId>orc-core</artifactId>
       <version>1.7.1</version>
     </dependency>
     <dependency>
       <groupId>org.apache.hadoop</groupId>
       <artifactId>hadoop-common</artifactId>
       <version>3.3.1</version>
     </dependency>
     <dependency>
       <groupId>org.apache.hadoop</groupId>
       <artifactId>hadoop-client-runtime</artifactId>
       <version>3.3.1</version>
     </dependency>
     <dependency>
       <groupId>com.google.protobuf</groupId>
       <artifactId>protobuf-java</artifactId>
       <version>${protobuf.version}</version>
     </dependency>
     <dependency>
       <groupId>io.grpc</groupId>
       <artifactId>grpc-netty-shaded</artifactId>
       <version>${grpc.version}</version>
     </dependency>
     <dependency>
       <groupId>io.grpc</groupId>
       <artifactId>grpc-protobuf</artifactId>
       <version>${grpc.version}</version>
     </dependency>
     <dependency>
       <groupId>io.grpc</groupId>
       <artifactId>grpc-stub</artifactId>
       <version>${grpc.version}</version>
     </dependency>
     <dependency>
       <groupId>io.grpc</groupId>
       <artifactId>grpc-services</artifactId>
       <version>${grpc.version}</version>
     </dependency>
     <dependency>
       <groupId>io.grpc</groupId>
       <artifactId>grpc-testing</artifactId>
       <version>${grpc.version}</version>
     </dependency>
     <dependency>
       <groupId>javax.annotation</groupId>
       <artifactId>javax.annotation-api</artifactId>
       <version>1.3.2</version>
     </dependency>
     <dependency>
       <groupId>com.google.protobuf</groupId>
       <artifactId>protobuf-java-util</artifactId>
       <version>${protobuf.version}</version>
     </dependency>
   </dependencies>
 
   <build>
     <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
       <plugins>
         <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
         <plugin>
           <artifactId>maven-clean-plugin</artifactId>
           <version>3.1.0</version>
         </plugin>
         <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
         <plugin>
           <artifactId>maven-resources-plugin</artifactId>
           <version>3.0.2</version>
         </plugin>
         <plugin>
           <artifactId>maven-compiler-plugin</artifactId>
           <version>3.8.0</version>
           <configuration>
             <source>11</source>
             <target>11</target>
             <compilerArgs>
               <arg>-verbose</arg>
               <arg>-Xlint:all</arg>
             </compilerArgs>
           </configuration>
         </plugin>
         <plugin>
           <artifactId>maven-surefire-plugin</artifactId>
           <version>2.22.2</version>
         </plugin>
         <plugin>
             <artifactId>maven-failsafe-plugin</artifactId>
             <version>2.22.2</version>
         </plugin>
         <plugin>
           <artifactId>maven-jar-plugin</artifactId>
           <version>3.0.2</version>
         </plugin>
         <plugin>
           <artifactId>maven-install-plugin</artifactId>
           <version>2.5.2</version>
         </plugin>
         <plugin>
           <artifactId>maven-deploy-plugin</artifactId>
           <version>2.8.2</version>
         </plugin>
         <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
         <plugin>
           <artifactId>maven-site-plugin</artifactId>
           <version>3.7.1</version>
         </plugin>
         <plugin>
           <artifactId>maven-project-info-reports-plugin</artifactId>
           <version>3.0.0</version>
         </plugin>
         <plugin>
           <artifactId>maven-dependency-plugin</artifactId>
           <version>3.1.2</version>
         </plugin>
         <plugin>
           <artifactId>maven-assembly-plugin</artifactId>
           <version>3.3.0</version>
           <configuration>
             <archive>
               <manifest>
                 <mainClass>org.softwareheritage.graph.rpc.GraphServer</mainClass>
               </manifest>
             </archive>
             <descriptorRefs>
               <descriptorRef>jar-with-dependencies</descriptorRef>
             </descriptorRefs>
             <appendAssemblyId>false</appendAssemblyId>
           </configuration>
           <executions>
             <execution>
               <id>make-assembly</id> <!-- this is used for inheritance merges -->
               <phase>package</phase> <!-- bind to the packaging phase -->
               <goals>
                 <goal>single</goal>
               </goals>
             </execution>
           </executions>
       </plugin>
       <!-- Spotless code formatting tool -->
       <plugin>
         <groupId>com.diffplug.spotless</groupId>
         <artifactId>spotless-maven-plugin</artifactId>
         <version>2.22.1</version>
         <configuration>
           <formats>
             <format>
               <includes>
                 <include>*.md</include>
                 <include>.gitignore</include>
               </includes>
               <trimTrailingWhitespace/>
               <endWithNewline/>
               <indent>
                 <spaces>true</spaces>
                 <spacesPerTab>4</spacesPerTab>
               </indent>
             </format>
           </formats>
           <java>
             <removeUnusedImports/>
             <eclipse>
                 <version>4.16.0</version>
                 <file>.coding-style.xml</file>
             </eclipse>
           </java>
         </configuration>
       </plugin>
       </plugins>
     </pluginManagement>
     <plugins>
       <plugin>
         <groupId>pl.project13.maven</groupId>
         <artifactId>git-commit-id-plugin</artifactId>
         <version>3.0.1</version>
         <executions>
           <execution>
             <id>get-the-git-infos</id>
             <goals>
               <goal>revision</goal>
             </goals>
             <phase>initialize</phase>
           </execution>
         </executions>
         <configuration>
           <verbose>true</verbose>
           <offline>true</offline>
           <useNativeGit>true</useNativeGit>
           <gitDescribe>
             <always>true</always>
             <match>v*</match>
           </gitDescribe>
           <replacementProperties>
             <replacementProperty>
               <property>git.closest.tag.name</property>
               <token>^v</token>
               <value></value>
               <regex>true</regex>
             </replacementProperty>
           </replacementProperties>
         </configuration>
       </plugin>
       <plugin>
         <artifactId>maven-source-plugin</artifactId>
         <version>2.1.1</version>
         <executions>
           <execution>
             <id>bundle-sources</id>
             <phase>package</phase>
             <goals>
               <goal>jar-no-fork</goal>
               <goal>test-jar-no-fork</goal>
             </goals>
           </execution>
         </executions>
       </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-javadoc-plugin</artifactId>
         <version>3.3.1</version>
         <executions>
           <execution>
             <id>resource-bundles</id>
             <phase>package</phase>
             <goals>
               <!-- produce source artifact for main project sources -->
               <goal>resource-bundle</goal>
 
               <!-- produce source artifact for project test sources -->
               <goal>test-resource-bundle</goal>
             </goals>
             <configuration>
               <detectOfflineLinks>false</detectOfflineLinks>
             </configuration>
           </execution>
           <execution>
             <id>javadoc-jar</id>
             <phase>package</phase>
             <goals>
               <goal>jar</goal>
             </goals>
           </execution>
         </executions>
         <configuration>
           <includeDependencySources>true</includeDependencySources>
           <dependencySourceIncludes>
             <dependencySourceInclude>it.unimi.dsi:webgraph-big:*</dependencySourceInclude>
           </dependencySourceIncludes>
           <links>
             <link>https://webgraph.di.unimi.it/docs-big/</link>
             <link>https://dsiutils.di.unimi.it/docs/</link>
             <link>https://fastutil.di.unimi.it/docs/</link>
             <link>https://law.di.unimi.it/software/law-docs/</link>
           </links>
           <tags>
             <tag>
               <name>implSpec</name>
               <placement>a</placement>
               <head>Implementation Requirements:</head>
             </tag>
             <tag>
               <name>implNote</name>
               <placement>a</placement>
               <head>Implementation Note:</head>
             </tag>
           </tags>
         </configuration>
       </plugin>
         <plugin>
         <groupId>org.xolstice.maven.plugins</groupId>
         <artifactId>protobuf-maven-plugin</artifactId>
         <version>0.6.1</version>
         <configuration>
           <protocArtifact>com.google.protobuf:protoc:${protobuf.version}:exe:${os.detected.classifier}</protocArtifact>
           <pluginId>grpc-java</pluginId>
           <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
         </configuration>
         <executions>
           <execution>
             <goals>
               <goal>compile</goal>
               <goal>compile-custom</goal>
               <goal>test-compile</goal>
               <goal>test-compile-custom</goal>
             </goals>
           </execution>
         </executions>
       </plugin>
     </plugins>
       <extensions>
           <extension>
               <groupId>kr.motd.maven</groupId>
               <artifactId>os-maven-plugin</artifactId>
               <version>1.6.2</version>
           </extension>
       </extensions>
   </build>
 </project>
diff --git a/java/src/main/java/org/softwareheritage/graph/rpc/GraphServer.java b/java/src/main/java/org/softwareheritage/graph/rpc/GraphServer.java
index b7d19d9..64acfba 100644
--- a/java/src/main/java/org/softwareheritage/graph/rpc/GraphServer.java
+++ b/java/src/main/java/org/softwareheritage/graph/rpc/GraphServer.java
@@ -1,294 +1,293 @@
 package org.softwareheritage.graph.rpc;
 
 import com.google.protobuf.FieldMask;
 import com.martiansoftware.jsap.*;
 import io.grpc.Server;
 import io.grpc.Status;
 import io.grpc.netty.shaded.io.grpc.netty.NettyServerBuilder;
 import io.grpc.netty.shaded.io.netty.channel.ChannelOption;
 import io.grpc.stub.StreamObserver;
 import io.grpc.protobuf.services.ProtoReflectionService;
 import it.unimi.dsi.logging.ProgressLogger;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.softwareheritage.graph.SWHID;
 import org.softwareheritage.graph.SwhBidirectionalGraph;
 import org.softwareheritage.graph.compress.LabelMapBuilder;
 
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.Properties;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
 
 /**
  * Server that manages startup/shutdown of a {@code Greeter} server.
  */
 public class GraphServer {
     private final static Logger logger = LoggerFactory.getLogger(GraphServer.class);
 
     private final SwhBidirectionalGraph graph;
     private final int port;
     private final int threads;
     private Server server;
 
     /**
      * @param graphBasename the basename of the SWH graph to load
      * @param port the port on which the GRPC server will listen
      * @param threads the number of threads to use in the server threadpool
      */
     public GraphServer(String graphBasename, int port, int threads) throws IOException {
         this.graph = loadGraph(graphBasename);
         this.port = port;
         this.threads = threads;
     }
 
     /** Load a graph and all its properties. */
     public static SwhBidirectionalGraph loadGraph(String basename) throws IOException {
-        // TODO: use loadLabelledMapped() when https://github.com/vigna/webgraph-big/pull/5 is merged
-        SwhBidirectionalGraph g = SwhBidirectionalGraph.loadLabelled(basename, new ProgressLogger(logger));
+        SwhBidirectionalGraph g = SwhBidirectionalGraph.loadLabelledMapped(basename, new ProgressLogger(logger));
         g.loadContentLength();
         g.loadContentIsSkipped();
         g.loadPersonIds();
         g.loadAuthorTimestamps();
         g.loadCommitterTimestamps();
         g.loadMessages();
         g.loadTagNames();
         g.loadLabelNames();
         return g;
     }
 
     /** Start the RPC server. */
     private void start() throws IOException {
         server = NettyServerBuilder.forPort(port).withChildOption(ChannelOption.SO_REUSEADDR, true)
                 .executor(Executors.newFixedThreadPool(threads)).addService(new TraversalService(graph))
                 .addService(ProtoReflectionService.newInstance()).build().start();
         logger.info("Server started, listening on " + port);
         Runtime.getRuntime().addShutdownHook(new Thread(() -> {
             try {
                 GraphServer.this.stop();
             } catch (InterruptedException e) {
                 e.printStackTrace(System.err);
             }
         }));
     }
 
     private void stop() throws InterruptedException {
         if (server != null) {
             server.shutdown().awaitTermination(30, TimeUnit.SECONDS);
         }
     }
 
     /**
      * Await termination on the main thread since the grpc library uses daemon threads.
      */
     private void blockUntilShutdown() throws InterruptedException {
         if (server != null) {
             server.awaitTermination();
         }
     }
 
     private static JSAPResult parseArgs(String[] args) {
         JSAPResult config = null;
         try {
             SimpleJSAP jsap = new SimpleJSAP(LabelMapBuilder.class.getName(), "",
                     new Parameter[]{
                             new FlaggedOption("port", JSAP.INTEGER_PARSER, "50091", JSAP.NOT_REQUIRED, 'p', "port",
                                     "The port on which the server should listen."),
                             new FlaggedOption("threads", JSAP.INTEGER_PARSER, "0", JSAP.NOT_REQUIRED, 't', "threads",
                                     "The number of concurrent threads. 0 = number of cores."),
                             new UnflaggedOption("graphBasename", JSAP.STRING_PARSER, JSAP.REQUIRED,
                                     "Basename of the output graph")});
 
             config = jsap.parse(args);
             if (jsap.messagePrinted()) {
                 System.exit(1);
             }
         } catch (JSAPException e) {
             e.printStackTrace();
         }
         return config;
     }
 
     /** Main launches the server from the command line. */
     public static void main(String[] args) throws IOException, InterruptedException {
         JSAPResult config = parseArgs(args);
         String graphBasename = config.getString("graphBasename");
         int port = config.getInt("port");
         int threads = config.getInt("threads");
         if (threads == 0) {
             threads = Runtime.getRuntime().availableProcessors();
         }
 
         final GraphServer server = new GraphServer(graphBasename, port, threads);
         server.start();
         server.blockUntilShutdown();
     }
 
     /** Implementation of the Traversal service, which contains all the graph querying endpoints. */
     static class TraversalService extends TraversalServiceGrpc.TraversalServiceImplBase {
         SwhBidirectionalGraph graph;
 
         public TraversalService(SwhBidirectionalGraph graph) {
             this.graph = graph;
         }
 
         /** Return various statistics on the overall graph. */
         @Override
         public void stats(StatsRequest request, StreamObserver<StatsResponse> responseObserver) {
             StatsResponse.Builder response = StatsResponse.newBuilder();
             response.setNumNodes(graph.numNodes());
             response.setNumEdges(graph.numArcs());
 
             Properties properties = new Properties();
             try {
                 properties.load(new FileInputStream(graph.getPath() + ".properties"));
                 properties.load(new FileInputStream(graph.getPath() + ".stats"));
             } catch (IOException e) {
                 throw new RuntimeException(e);
             }
             response.setCompressionRatio(Double.parseDouble(properties.getProperty("compratio")));
             response.setBitsPerNode(Double.parseDouble(properties.getProperty("bitspernode")));
             response.setBitsPerEdge(Double.parseDouble(properties.getProperty("bitsperlink")));
             response.setAvgLocality(Double.parseDouble(properties.getProperty("avglocality")));
             response.setIndegreeMin(Long.parseLong(properties.getProperty("minindegree")));
             response.setIndegreeMax(Long.parseLong(properties.getProperty("maxindegree")));
             response.setIndegreeAvg(Double.parseDouble(properties.getProperty("avgindegree")));
             response.setOutdegreeMin(Long.parseLong(properties.getProperty("minoutdegree")));
             response.setOutdegreeMax(Long.parseLong(properties.getProperty("maxoutdegree")));
             response.setOutdegreeAvg(Double.parseDouble(properties.getProperty("avgoutdegree")));
             responseObserver.onNext(response.build());
             responseObserver.onCompleted();
         }
 
         /** Return a single node and its properties. */
         @Override
         public void getNode(GetNodeRequest request, StreamObserver<Node> responseObserver) {
             SwhBidirectionalGraph g = graph.copy();
             long nodeId;
             try {
                 nodeId = g.getNodeId(new SWHID(request.getSwhid()));
             } catch (IllegalArgumentException e) {
                 responseObserver
                         .onError(Status.INVALID_ARGUMENT.withDescription(e.getMessage()).withCause(e).asException());
                 return;
             }
             Node.Builder builder = Node.newBuilder();
             NodePropertyBuilder.buildNodeProperties(g.getForwardGraph(), request.hasMask() ? request.getMask() : null,
                     builder, nodeId);
             responseObserver.onNext(builder.build());
             responseObserver.onCompleted();
         }
 
         /** Perform a BFS traversal from a set of source nodes and stream the nodes encountered. */
         @Override
         public void traverse(TraversalRequest request, StreamObserver<Node> responseObserver) {
             SwhBidirectionalGraph g = graph.copy();
             Traversal.SimpleTraversal t;
             try {
                 t = new Traversal.SimpleTraversal(g, request, responseObserver::onNext);
             } catch (IllegalArgumentException e) {
                 responseObserver
                         .onError(Status.INVALID_ARGUMENT.withDescription(e.getMessage()).withCause(e).asException());
                 return;
             }
             t.visit();
             responseObserver.onCompleted();
         }
 
         /**
          * Find the shortest path between a set of source nodes and a node that matches a given criteria
          * using a BFS.
          */
         @Override
         public void findPathTo(FindPathToRequest request, StreamObserver<Path> responseObserver) {
             SwhBidirectionalGraph g = graph.copy();
             Traversal.FindPathTo t;
             try {
                 t = new Traversal.FindPathTo(g, request);
             } catch (IllegalArgumentException e) {
                 responseObserver
                         .onError(Status.INVALID_ARGUMENT.withDescription(e.getMessage()).withCause(e).asException());
                 return;
             }
             t.visit();
             Path path = t.getPath();
             if (path == null) {
                 responseObserver.onError(Status.NOT_FOUND.asException());
             } else {
                 responseObserver.onNext(path);
                 responseObserver.onCompleted();
             }
         }
 
         /**
          * Find the shortest path between a set of source nodes and a set of destination nodes using a
          * bidirectional BFS.
          */
         @Override
         public void findPathBetween(FindPathBetweenRequest request, StreamObserver<Path> responseObserver) {
             SwhBidirectionalGraph g = graph.copy();
             Traversal.FindPathBetween t;
             try {
                 t = new Traversal.FindPathBetween(g, request);
             } catch (IllegalArgumentException e) {
                 responseObserver
                         .onError(Status.INVALID_ARGUMENT.withDescription(e.getMessage()).withCause(e).asException());
                 return;
             }
             t.visit();
             Path path = t.getPath();
             if (path == null) {
                 responseObserver.onError(Status.NOT_FOUND.asException());
             } else {
                 responseObserver.onNext(path);
                 responseObserver.onCompleted();
             }
         }
 
         /** Return the number of nodes traversed by a BFS traversal. */
         @Override
         public void countNodes(TraversalRequest request, StreamObserver<CountResponse> responseObserver) {
             AtomicLong count = new AtomicLong(0);
             SwhBidirectionalGraph g = graph.copy();
             TraversalRequest fixedReq = TraversalRequest.newBuilder(request)
                     // Ignore return fields, just count nodes
                     .setMask(FieldMask.getDefaultInstance()).build();
             Traversal.SimpleTraversal t;
             try {
                 t = new Traversal.SimpleTraversal(g, fixedReq, n -> count.incrementAndGet());
             } catch (IllegalArgumentException e) {
                 responseObserver
                         .onError(Status.INVALID_ARGUMENT.withDescription(e.getMessage()).withCause(e).asException());
                 return;
             }
             t.visit();
             CountResponse response = CountResponse.newBuilder().setCount(count.get()).build();
             responseObserver.onNext(response);
             responseObserver.onCompleted();
         }
 
         /** Return the number of edges traversed by a BFS traversal. */
         @Override
         public void countEdges(TraversalRequest request, StreamObserver<CountResponse> responseObserver) {
             AtomicLong count = new AtomicLong(0);
             SwhBidirectionalGraph g = graph.copy();
             TraversalRequest fixedReq = TraversalRequest.newBuilder(request)
                     // Force return empty successors to count the edges
                     .setMask(FieldMask.newBuilder().addPaths("num_successors").build()).build();
             Traversal.SimpleTraversal t;
             try {
                 t = new Traversal.SimpleTraversal(g, fixedReq, n -> count.addAndGet(n.getNumSuccessors()));
             } catch (IllegalArgumentException e) {
                 responseObserver
                         .onError(Status.INVALID_ARGUMENT.withDescription(e.getMessage()).withCause(e).asException());
                 return;
             }
             t.visit();
             CountResponse response = CountResponse.newBuilder().setCount(count.get()).build();
             responseObserver.onNext(response);
             responseObserver.onCompleted();
         }
     }
 }