Change Details

The `known` flag from `IsochroneNode` is no longer being used and `maxdate` calculation can thus be simplified, Isochrone graph related tests are updated as well to reflect the changes.

The `known` flag from `IsochroneNode` is no longer being used, and `maxdate` calculation can thus be simplified. Isochrone graph related tests are updated as well to reflect the changes.

The `known` flag from `IsochroneNode` is no longer being used, and `maxdate` calculation can thus be simplified,. Isochrone graph related tests are updated as well to reflect the changes.