docs: def _find_dependent_modules(self, module):
          """
          Return the set of dependent modules for used modules,
          classes and routines.
          """
          dms = set()
          for um in inspect.getmembers(module, inspect.ismodule):
              dms.add(um[1])
  
          for uc in inspect.getmembers(module, inspect.isclass):
              self._add_obj_module(dms, uc[1])
          for ur in inspect.getmembers(module, inspect.isroutine):
              self._add_obj_module(dms, ur[1])
  
          return dms