anchor.diff:  gremlin> g.V(4).outE()  // all outgoing edges
   ==>e[10][4-created->5]
   ==>e[11][4-created->3]
  -gremlin> g.V(4).outE(1)  // at most one outgoing edge per incoming vertex
  -==>e[10][4-created->5]
   gremlin> g.V(4).inE('knows')  // all incoming knows-edges
   ==>e[8][1-knows->4]
   gremlin> g.V(4).inE('created') // all incoming created-edges
  
positive.code: ==>v[1]
  ==>v[2]
  ==>v[3]
  ==>v[4]
  gremlin> g.V().range(1,3)
  ==>v[2]
  ==>v[3]
  ==>v[4]
  gremlin> g.V().as('a').both().jump('a',1000000).range(6,10)
  ==>v[1]
  ==>v[1]
  ==>v[1]
  ==>v[1]
  
negative.code: gremlin> g.V(1).out('created') // what has marko created?
  ==>v[3]
  gremlin> g.V(1).out('created').aggregate('x') // aggregate all his creations
  ==>{v[3]}
  gremlin> g.V(1).out('created').aggregate('x').in('created') // who are marko's collaborators
  ==>v[1]
  ==>v[4]
  