src/vs/editor/common/model/pieceTreeTextBuffer/pieceTreeTextBuffer.ts/PieceTreeTextBuffer/getLineFirstNonWhitespaceColumn
class PieceTreeTextBuffer:	public getLineFirstNonWhitespaceColumn(lineNumber: number): number {
		const result = strings.firstNonWhitespaceIndex(this.getLineContent(lineNumber));
		if (result === -1) {
			return 0;
		}
		return result + 1;
	}