src/vs/editor/contrib/snippet/browser/snippetSession.ts/OneSnippet/isTrivialSnippet
class OneSnippet:	get isTrivialSnippet(): boolean {
		if (this._snippet.placeholders.length === 0) {
			return true;
		}
		if (this._snippet.placeholders.length === 1) {
			const [placeholder] = this._snippet.placeholders;
			if (placeholder.isFinalTabstop) {
				if (this._snippet.rightMostDescendant === placeholder) {
					return true;
				}
			}
		}
		return false;
	}