code: def SetValue(self, identifier, value):
      
      if not isinstance(identifier, py2to3.STRING_TYPES):
        raise TypeError('Identifier not a string type.')
  
      identifier = identifier.lower()
      self._values[identifier] = value
docs: Sets a value by identifier.
  
      Args:
        identifier (str): case insensitive unique identifier for the value.
        value (object): value.
  
      Raises:
        TypeError: if the identifier is not a string type.