public final class BuilderKey extends java.lang.Object implements TraversalBuildStep
Helper class that is only used to identify a
TraversalBuilder in a
reason why this is needed is because the builder is referenced at various places, while it needs to be mutated.
In an immutable data structure this is best done with an indirection, i.e. places refer to this immutable key and
look up the current state in an extra Map.
See comments in akka.stream.impl.package for more details.
|Constructor and Description|