    def _update_focus(self, column, widget, set_focus=True):
        """
        Helper function to move focus if new state matches the passed in state.

        :param column: Old index of column with focus.
        :param widget: Old index of widget with focus.
        :param set_focus: Whether to set a new focus or not.
        """
        if (column, widget) != (self._live_col, self._live_widget):
            self._columns[column][widget].blur()
            if set_focus:
                self._columns[self._live_col][self._live_widget].focus()
Helper function to move focus if new state matches the passed in state.

:param column: Old index of column with focus.
:param widget: Old index of widget with focus.
:param set_focus: Whether to set a new focus or not.
asciimatics/widgets/layout.py