The SavedHistory is used to persist the actions of a user on the topology map in order to achieve:

• clicking forward (->) and backwards (<-) buttons on the Topology Map

• Reload the latest state when coming back to the Topology Map

However the implementation does not support the nodes in focus or better vertices in focus correctly.

The problem here is, that there are no vertices in focus, but executed search queries.
Each executed SearchQuery results in usually one VertexHopCriteria object.
Each VertexHopCriteria represents the vertices in focus.
But as it already states there can be more than one.
As soon as the implementation returns more than one vertex, the SavedHistory saves the vertices in focus but does not persist the history correctly.
This results in selecting the right vertices in focus but not restoring the SearchResults correctly.