code: def _write_widget(self, val):
          
          self._itsme = True
          try:
              setter = self._wid_info[self._wid][1]
              wtype = self._wid_info[self._wid][2]
              if setter:
                  if wtype is not None:
                      setter(self._wid, self._cast_value(val, wtype))
                  else:
                      setter(self._wid, val)
          finally:
              self._itsme = False
docs: Writes value into the widget. If specified, user setter
          is invoked.