doctests failing #942

reading sources... [ 26%] generated/control.flatsys.solve_flat_ocp
/home/runner/work/python-control/python-control/control/statesp.py:docstring of control.statesp.StateSpace.__call__:1: WARNING: duplicate object description of control.StateSpace.__call__, other instance in generated/control.StateSpace, use :no-index: for one of them
/home/runner/work/python-control/python-control/control/xferfcn.py:docstring of control.xferfcn.TransferFunction.__call__:1: WARNING: duplicate object description of control.TransferFunction.__call__, other instance in generated/control.TransferFunction, use :no-index: for one of them
ERROR: [numpydoc] While processing docstring for 'control.forced_response'

Extension error (numpydoc.numpydoc):
Handler <function mangle_docstrings at 0x7fa850237ec0> for event 'autodoc-process-docstring' threw an exception (exception: Expected a class or None, but got <function forced_response at 0x7fa853992ac0>)
make: *** [Makefile:32: html] Error 2