code: public static Titan1Vertex createVertex(Titan1Graph graph, Vertex source) {
  
          if (source == null) {
              return null;
          }
          return new Titan1Vertex(graph, source);
      }
docs: Creates a Titan1Vertex that corresponds to the given Gremlin Vertex.
  
  @param graph The graph that contains the vertex
  @param source the Gremlin vertex