src/vs/workbench/services/preferences/browser/keybindingsEditorModel.ts/KeybindingItemMatches/isModifier
class KeybindingItemMatches:	private isModifier(word: string): boolean {
		if (this.wordMatchesAltModifier(word)) {
			return true;
		}
		if (this.wordMatchesCtrlModifier(word)) {
			return true;
		}
		if (this.wordMatchesMetaModifier(word)) {
			return true;
		}
		if (this.wordMatchesShiftModifier(word)) {
			return true;
		}
		return false;
	}