code: def get_function_class(function_name):
      
  
      if function_name in _known_functions:
  
          return _known_functions[function_name]
  
      else:
  
          raise UnknownFunction("Function %s is not known. Known functions are: %s" %
                                (function_name, ",".join(_known_functions.keys())))
docs: Return the type for the requested function
  
      :param function_name: the function to return
      :return: the type for that function (i.e., this is a class, not an instance)