tinkerpop/blueprints — pull request #186 by karussell (2011-11-15 23:10:16+00:00)
Title: Make the in-memory TinkerGraph more thread safe

Not sure if this is sufficient though ... have a look, please! all tests still pass :)

also:

* putted serialversions to avoid parsing errors if classes change only slightly (if classes have major changes one needs to edit those constants)
* ConcurrenthashMap does not support null values => NULL object
* no ConcurrentHashSet => MySet.create

BTW: one further mini enhancement: why it is necessary to check up front if value exists in addEdge? just put the value and check if it returns null ..