None value with variable "qd" and "qdd" in function "mstraj" return

Describe the bug
I applied the function "mstraj" in my code,

Version information
Installation from Conda channel "conda-forge"

To Reproduce
The python code is below:

q_start = np.array([0, 0, 0, 0, 0, 0])
q_via1 = np.array([0.5, -0.5, 0.2, 0, 0, 0])
q_via2 = np.array([1.0, 0.5, 0.9, 0.5, -0.2, 0])
q_end = np.array([1.5, 0, 0, 0, 0, 0])
waypoints = np.array([q_start, q_via1, q_via2, q_end])

dt = 0.02
t_acc = 0.5
q_vel = 2

traj = rtb.mstraj(waypoints, dt=dt, tacc=t_acc, qdmax=q_vel)

# None in variable "qd" and "qdd"
print(traj.qd)
print(traj.qdd)

The output of the code:

None
None

Expected behavior
I expected the meaningful value of varibale "qd" and "qdd" but returns "None".

Screenshots

Environment (please complete the following information):

• Linux (Ubuntu 22.04).
• python==3.11.11

Additional context

Start at the rtb.mstraj entry point using the supplied waypoint example and inspect how the returned trajectory exposes qd and qdd. Compare the documented or expected trajectory outputs with the reproduced None values, then add a regression test showing the intended values are returned.