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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def set_xattr(self, path, xattr_name, xattr_value, flag, **kwargs):
 """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`` """

        kwargs['xattr.name'] = xattr_name
        kwargs['xattr.value'] = xattr_value
        response = self._put(path, 'SETXATTR', flag=flag, **kwargs)
        assert not response.content