src/vs/workbench/contrib/notebook/browser/view/renderers/webviewPreloads.ts/CSSHighlighter/highlightCurrentMatch
class CSSHighlighter:		highlightCurrentMatch(index: number): void {
			this._findMatchIndex = index;
			const match = this.matches[this._findMatchIndex];
			const range = match.originalRange;

			if (match) {
				let offset = 0;
				try {
					const outputOffset = document.getElementById(match.id)!.getBoundingClientRect().top;
					const rangeOffset = match.originalRange.getBoundingClientRect().top;
					offset = rangeOffset - outputOffset;
					postNotebookMessage('didFindHighlight', {
						offset
					});
				} catch (e) {
				}
			}

			this._currentMatchesHighlight.clear();
			this._currentMatchesHighlight.add(range);
		}