def join(self, other: _ClientList, offset_to_current: int = 0) -> None:
        """
        Add clients from 'other' _ClientList to self.
        'offset_to_current' works as described for add()
        """
        pos = max(0, self.current_index + offset_to_current)
        if pos < len(self.clients):
            self.clients = self.clients[:pos:] + other.clients + self.clients[pos::]
        else:
            self.clients.extend(other.clients)

        Add clients from 'other' _ClientList to self.
        'offset_to_current' works as described for add()
        
libqtile/layout/base.py