code: def set(self, value):
          
  
          if not isinstance(value, str_cls):
              raise TypeError(unwrap(
                  '''
                  %s value must be a unicode string, not %s
                  ''',
                  type_name(self),
                  type_name(value)
              ))
  
          self._unicode = value
          self.contents = iri_to_uri(value)
          self._header = None
          if self._trailer != b'':
              self._trailer = b''
docs: Sets the value of the string
  
          :param value:
              A unicode string