def METHOD_NAME(self):
    position = self.data.qpos.flat.copy()
    velocity = self.data.qvel.flat.copy()
    if self._exclude_current_positions_from_observation:
        position = position[2:]
    if self._use_contact_forces:
        contact_force = self.contact_forces.flat.copy()
        return np.concatenate((position, velocity, contact_force))
    else:
        return np.concatenate((position, velocity))