    def transform_action_inv(self, action: np.ndarray):
        """
        Transform action from spatial(base) frame into body(end-effector) frame
        using the adjoint matrix.
        """
        action = np.array(action)
        action[:6] = np.linalg.inv(self.adjoint_matrix) @ action[:6]
        return action
Transform action from spatial(base) frame into body(end-effector) frame
using the adjoint matrix.
serl_robot_infra/franka_env/envs/relative_env.py