def difference(self, other):
        """
        In-place difference with *other* set.
        """
        context = self._context
        builder = self._builder
        payload = self.payload
        other_payload = other.payload

        with other_payload._iterate() as loop:
            entry = loop.entry
            self._remove_key(payload, entry.key, entry.hash, do_resize=False)

        # Final downsize
        self.downsize(payload.used)

        In-place difference with *other* set.
        
numba/cpython/setobj.py