code: public int getConnection(String connectionModel, String nodeType, int ordinal, String propertyName) {
      	int connectionModelIndex = modelHolder.getModelIndex(connectionModel);
          return getConnection(connectionModelIndex, nodeType, ordinal, propertyName);
      }
docs: Retrieve a single connected ordinal in a given connection model, given the type and ordinal of the originating node, and the property by which this node is connected.
  
  @return the connected ordinal, or -1 if there is no such ordinal