Tests fail because P.Within() arguments are wrapped in an array in Gremlin.Net

For the scenario g_V_hasIdXwithinXemptyXX_count, P.within([]) will be serialized as:

{
    "@type": "g:P",
    "@value": {
        "predicate": "within",
        "value": [
            []
        ]
    }
}

which fails on the server side as it tries to treat [] as an id:
Expected an id that is convertible to Integer but received class java.util.ArrayList.

This seems to be related to the changes made in TINKERPOP-1874.