def from_ros_pose_msg(pose_msg,
                          from_frame='unassigned',
                          to_frame='world'):
        """Creates a RigidTransform from a ROS pose msg. 
        
        Parameters
        ----------
        pose_msg : :obj:`geometry_msgs.msg.Pose`
            ROS pose message
        """
        quaternion = np.array([pose_msg.orientation.w,
                               pose_msg.orientation.x,
                               pose_msg.orientation.y,
                               pose_msg.orientation.z])
        position = np.array([pose_msg.position.x,
                             pose_msg.position.y,
                             pose_msg.position.z])
        pose = RigidTransform(rotation=quaternion,
                              translation=position,
                              from_frame=from_frame,
                              to_frame=to_frame)
        return pose
Creates a RigidTransform from a ROS pose msg. 
        
        Parameters
        ----------
        pose_msg : :obj:`geometry_msgs.msg.Pose`
            ROS pose message