The deleteGraph method doesn't take into account created constraints on the metaLabel. Problem is that DETACH DELETE doesn't remove associated constraints and indexes. That causes an error when a PropertyGraph with the same name is deleted and written back again. See the following example:

val neo4jSource = GraphSources.cypher.neo4j(neo4jConfig)
val name = GraphName("arbitraryGraph")
neo4jSource.store(name, graph)
neo4jSource.delete(name)
neo4jSource.store(name, graph)

That causes the following exception:

Exception in thread "main" org.opencypher.okapi.impl.exception.GraphAlreadyExistsException: A graph with name arbitraryGraph is already stored in this graph data source.

Moreover, it doesn't allow write a PropertyGraph with entireGraphName, which makes no sense to me. What if I would like just store everything to the database and never restore that PropertyGraph (so metaLabel and related properties, i.e. ___morpheusID are not desired to be saved), because I have other data sources and graph database is the destination of the processed data?