docs: def governor(self, dep_type, node):
          """
          Registers a node as governing this node
  
          :param dep_type: The dependency type
          :type dep_type: str
          :param node:
  
          :return: self, provides fluent interface
          :rtype: corenlp_xml.dependencies.DependencyNode
  
          """
          self._governors[dep_type] = self._governors.get(dep_type, []) + [node]
          return self