> MeanAngle( [ 350, 10 ] *~ Unit(arcdeg) );
                                   0.

> MeanAngle( [ 90, 180, 270, 360 ] *~ Unit(arcdeg) );
                                   0.

> MeanAngle( [ 10, 20, 30 ] *~ Unit(arcdeg) );
                              20.00000000