docs: def SetFocus(self, **kwargs):
          """
          Over-rides normal behaviour of shifting focus to any child.  Prefers
          the one set explicityly by use_as_focus.
          :param **kwargs:
          """
          if self._focus is not None:
              self._focus.SetFocus()
          else:
              # fall back on the default behaviour
              super(_FocusablePanel, self).SetFocus()