Unexpected type returned from efforts

We have recently started to look into robotics api in Isaac sim. and found a discrepancy between the docs and the result:
Looking at the documentation the JointsState’s effort member is a np.ndarray.
But after running some tests we are getting it as a list.


            joints_states = self.franka.get_joints_state()
            print(f'positions: {joints_states.positions}')
            print(f'positions shape: {joints_states.positions.shape}')
            print(f'velocities: {joints_states.velocities}')
            print(f'velocities shape: {joints_states.velocities.shape}')
            print(f'efforts: {joints_states.efforts}')
            print(f'efforts shape: {joints_states.efforts.shape}')


positions: [ 1.2048536e-02 -5.6951332e-01  8.3364430e-05 -2.8116686e+00
 -3.2714659e-03  3.0283213e+00  7.5724059e-01  3.9959631e+00
positions shape: (9,)
velocities: [-0.00085996 -0.01000252 -0.00161272  0.03379822  0.02702826  0.04456121
 -0.02863449  0.0208592   0.00028469]
velocities shape: (9,)
efforts: [0.019438474, -71716.45, -5503.964, 187911.56, 7982.7075, 18532.047, -401.812, 0.3106301, -0.31062558]
'list' object has no attribute 'shape'