anchor.diff:  ----
   
   The above is interesting in that it demonstrates the use of referencing the internal `Map<Object,Long>` of `groupCount()` with a string variable. Given that `groupCount()` is a sideEffect-step, it simply passes the object it received to its output. Internal to `groupCount()`, the object's count is incremented.
  -
  -WARNING: The `groupCount()`-step does not have a correlate in <<traversalvertexprogram,Gremlin OLAP>> when used mid-traversal. When in mid-traversal grouping only occurs at the the current processing vertex and thus, is not a global operation as it in Gremlin OLTP. However, `GroupCountMapReduce` provides unified groups at the end of the traversal computation.
   
   [[has-step]]
   Has Step
  
positive.code: g.V().dedup().by(label).values('name')
  ----
  
  WARNING: The `dedup()`-step does not have a correlate in <<traversalvertexprogram,Gremlin OLAP>> when used mid-traversal. When in mid-traversal de-duplication only occurs at the the current processing vertex and thus, is not a global operation as it in Gremlin OLTP. When `dedup()` is an end step, the resultant traversers are de-duplicated by `TraverserMapReduce`.
  
  [[drop-step]]
  Drop Step
  ~~~~~~~~~
  
negative.code: . Value-projection: What feature of the group to store in the key-list?
  . Reduce-projection: What feature of the key-list to ultimately return?
  
  [[groupcount-step]]
  GroupCount Step
  ~~~~~~~~~~~~~~~
  