code: def pop(self, key, default=NO_DEFAULT):
          
          if key not in self and default != NO_DEFAULT:
              return default
          value = self[key]
          self.__delitem__(key)
          return value
docs: If key is in the flat dictionary, remove it and return its value,
          else return default. If default is not given and key is not in the
          dictionary, :exc:`KeyError` is raised.
  
          :param mixed key: The key name
          :param mixed default: The default value
          :rtype: mixed