src/vs/editor/common/model/pieceTreeTextBuffer/pieceTreeTextBuffer.ts/PieceTreeTextBuffer/getValueLengthInRange
class PieceTreeTextBuffer:	public getValueLengthInRange(range: Range, eol: EndOfLinePreference = EndOfLinePreference.TextDefined): number {
		if (range.isEmpty()) {
			return 0;
		}

		if (range.startLineNumber === range.endLineNumber) {
			return (range.endColumn - range.startColumn);
		}

		const startOffset = this.getOffsetAt(range.startLineNumber, range.startColumn);
		const endOffset = this.getOffsetAt(range.endLineNumber, range.endColumn);
		return endOffset - startOffset;
	}