code: def set_xattr(self, path, xattr_name, xattr_value, flag, **kwargs):
          
          kwargs['xattr.name'] = xattr_name
          kwargs['xattr.value'] = xattr_value
          response = self._put(path, 'SETXATTR', flag=flag, **kwargs)
          assert not response.content
docs: Set an xattr of a file or directory.
  
          :param xattr_name: The name must be prefixed with the namespace followed by ``.``. For
              example, ``user.attr``.
          :param flag: ``CREATE`` or ``REPLACE``