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