src/vs/base/browser/ui/selectBox/selectBoxCustom.ts/SelectBoxList/onEnter
class SelectBoxList:	private onEnter(e: StandardKeyboardEvent): void {
		dom.EventHelper.stop(e);

		// Only fire if selection change
		if (this.selected !== this._currentSelection) {
			this._currentSelection = this.selected;
			this._onDidSelect.fire({
				index: this.selectElement.selectedIndex,
				selected: this.options[this.selected].text
			});
			if (!!this.options[this.selected] && !!this.options[this.selected].text) {
				this.selectElement.title = this.options[this.selected].text;
			}
		}

		this.hideSelectDropDown(true);
	}