code: def get_observing_methods(self, prop_name):
          
          # searches in pattern and in map
          return (functools.reduce(set.union,
                                   (meths
                                    for pat, meths in self.__PAT_TO_METHS.items()
                                    if fnmatch.fnmatch(prop_name, pat)),
                                   set()) |
                  self.__PROP_TO_METHS.get(prop_name, set()))
docs: Return a possibly empty set of callables registered with
          :meth:`observe` for *prop_name*. The returned set includes
          those notifications which have been registered by means of
          patterns matching prop_name.
  
          .. versionadded:: 1.99.1
             Replaces :meth:`get_custom_observing_methods`.