Method setdefault

django/http/request.py:702–706

(self, key, default=None)

        super().clear()

    def setdefault(self, key, default=None):
        self._assert_mutable()
        key = bytes_to_text(key, self.encoding)
        default = bytes_to_text(default, self.encoding)
        return super().setdefault(key, default)

    def copy(self):
        """Return a mutable copy of this object."""