src/vs/editor/contrib/snippet/browser/snippetSession.ts/SnippetSession/getEnclosingRange
class SnippetSession:	public getEnclosingRange(): Range | undefined {
		let result: Range | undefined;
		for (const snippet of this._snippets) {
			const snippetRange = snippet.getEnclosingRange();
			if (!result) {
				result = snippetRange;
			} else {
				result = result.plusRange(snippetRange!);
			}
		}
		return result;
	}