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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pose2mat(pose):
 """ Converts pose to homogeneous matrix. Args: pose: a (pos, orn) tuple where pos is vec3 float cartesian, and orn is vec4 float quaternion. Returns: 4x4 homogeneous matrix """

    homo_pose_mat = np.zeros((4, 4), dtype=np.float32)
    homo_pose_mat[:3, :3] = quat2mat(pose[1])
    homo_pose_mat[:3, 3] = np.array(pose[0], dtype=np.float32)
    homo_pose_mat[3, 3] = 1.
    return homo_pose_mat