This caused the following warning:
WARNING cassandra.protocol:libevreactor.py:361 Server warning: `USE <keyspace>` with prepared statements is considered to be an anti-pattern due to ambiguity in non-qualified table names. Please consider removing instances of `Session#setKeyspace(<keyspace>)`, `Session#execute("USE <keyspace>")` and `cluster.newSession(<keyspace>)` from your code, and always use fully qualified table names (e.g. <keyspace>.<table>).
This also prepends 'test' to the name of keyspaces used in tests, so
they are guaranteed to start with an letter (starting with digits cause
syntax errors in most statements).
Depends on D8182.