code: def pop(self, identifier, default=None):
          
          if identifier in self.children:
              item = self[identifier]
              self.__delitem__(identifier)
              return item
          else:
              return default
docs: Pop a node of the AttrTree using its path string.
  
          Args:
              identifier: Path string of the node to return
              default: Value to return if no node is found
  
          Returns:
              The node that was removed from the AttrTree