code: public static JSONObject jsonFromElement(final AtlasElement element, final Set<String> propertyKeys,
                                               final AtlasGraphSONMode mode)
          throws JSONException {
  
          final AtlasGraphSONUtility graphson = element instanceof AtlasEdge
                  ? new AtlasGraphSONUtility(mode, null, propertyKeys)
                  : new AtlasGraphSONUtility(mode, propertyKeys, null);
          return graphson.jsonFromElement(element);
      }
docs: Creates a Jettison JSONObject from a graph element.
  
  @param element
  the graph element to convert to JSON.
  @param propertyKeys
  The property getPropertyKeys() at the root of the element to
  serialize. If null, then all getPropertyKeys() are serialized.
  @param mode
  the type of GraphSON to be generated.