def set_selected(self, selected):
        if not self._guard & SELECTED_GUARD:
            self._guard |= SELECTED_GUARD
            try:
                d = self.declaration
                try:
                    index = d.items.index(selected)
                except ValueError:
                    index = -1
                self.widget.setCurrentIndex(index)
            finally:
                self._guard &= ~SELECTED_GUARD
Set the selected object in the combo box.
dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/qt/qt_object_combo.py/QtObjectCombo.set_selected