src/vs/editor/common/languages/supports/richEditBrackets.ts/BracketsUtils/findPrevBracketInRange
class BracketsUtils:	public static findPrevBracketInRange(reversedBracketRegex: RegExp, lineNumber: number, lineText: string, startOffset: number, endOffset: number): Range | null {
		// Because JS does not support backwards regex search, we search forwards in a reversed string with a reversed regex ;)
		const reversedLineText = toReversedString(lineText);
		const reversedSubstr = reversedLineText.substring(lineText.length - endOffset, lineText.length - startOffset);
		return this._findPrevBracketInText(reversedBracketRegex, lineNumber, reversedSubstr, startOffset);
	}