@Override
        public void serialize(final Double doubleValue, final JsonGenerator jsonGenerator,
                              final SerializerProvider serializerProvider) throws IOException {
            jsonGenerator.writeNumber(doubleValue);
        }
GraphSON serializers for graph-based objects such as vertices, edges, properties, and paths. These serializers
present a generalized way to serialize the implementations of core interfaces.

@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/GraphSONSerializersV2.java