code: def _findGlyph(self, glyphName):
          
          found = []
          for key, groupList in self.items():
              if glyphName in groupList:
                  found.append(key)
          return found
docs: This is the environment implementation of
          :meth:`BaseGroups.findGlyph`. **glyphName** will be
          an :ref:`type-string`.
  
          Subclasses may override this method.