gremlin> g.mergeE([(Direction.from):44,(Direction.to):8]).
......1> option(onMatch,property('dist',union(values('dist'), __.constant(1)).sum()).constant([:])).valueMap(true)
==>[id:5062,label:route,dist:550]
gremlin> g.mergeE([(Direction.from):44,(Direction.to):8]).
......1> option(onMatch,property('dist',union(values('dist'), __.constant(1)).sum()).constant([:])).valueMap(true)
==>[id:5062,label:route,dist:550]