graphdb/src/main/java/com/tinkerpop/blueprints/impls/orient/OrientBaseGraph.java
@Override
  public OrientVertex addVertex(final Object id) {
    makeActive();

    return addVertex(id, (Object[]) null);
  }
@Override
  public OrientVertex addVertex(final Object id) {
    makeActive();

    return addVertex(id, (Object[]) null);
  }
Creates a new unconnected vertex with no fields in the Graph.

@param id Optional, can contains the Vertex's class name by prefixing with "class:"

@return The new OrientVertex created