I just got the beta version of your book in order to start playing with neo4j and it seems that Gremlin 1.4 and up no longer support the test filter shortcut mentioned in the book. I can’t point the page number because I’m reading it on Kindle but the paragraph reads:
“Testing for property equality is such a common filter, Gremelin provides a shortcut syntax [[..]], which accepts a key/value map to filter by. gremlin> g.V[[name: ‘riesling’]] ==> v “
When we try this we actually got a ‘no signature of method’ exception. The drop of this sortcut was confirmed in https://github.com/tinkerpop/gremlin/wiki/Release-Notes.