anchor.diff:  CAUTION: `EventStrategy` is not meant for usage in tracking global mutations across separate processes.  In other words, an mutation in what JVM process is not raised as an event in a different JVM process.  In addition, events are not raised when mutations occur outside of the `Traversal` context.
   
   PartitionStrategy
  -=================
  -
  -image::partition-graph.png[width=650]
  +~~~~~~~~~~~~~~~~~
  +
  +image::partition-graph.png[width=325]
   
   `PartitionStrategy` partitions the vertices and edges of a graph into `String` named partitions (i.e. buckets, subgraphs, etc.). The idea behind `PartitionStrategy` is presented in the image above where each element is in a single partition (represented by its color). Partitions can be read from, written to, and linked/joined by edges that span one or two partitions (e.g. a tail vertex in one partition and a head vertex in another).
   
  
positive.code: strategyA = PartitionStrategy.build().partitionKey("_partition").writePartition("a").addReadPartition("a").create()
  strategyB = PartitionStrategy.build().partitionKey("_partition").writePartition("b").addReadPartition("b").create()
  gA = GraphTraversalSource.build().with(strategyA).create(graph)
  gA.addV() //// this vertex has a property of {_partition:"a"}
  gB = GraphTraversalSource.build().with(strategyB).create(graph)
  gB.addV() //// this vertex has a property of {_partition:"b"}
  gA.V()
  gB.V()
  ----
  
negative.code: edgeCriterion = { edge -> (int) edge.id() >= 8 && (int) edge.id() <= 10}
  strategy = SubgraphStrategy.build().vertexPredicate(vertexCriterion).edgePredicate(edgeCriterion).create()
  g = GraphTraversalSource.build().with(strategy).create(graph)
  g.V() // shows all vertices as they all pass the vertexCriterion
  g.E() // shows only the edges defined in the edgeCriterion
  ----
  
  Note that `SubgraphStrategy` directly passes the edge and vertex criterion `Predicate` objects  to an injected `filter` step and as such may not take advantage of important optimizations provided by the various `Graph` implementations (given the use of lambda expressions).
  