src/vs/editor/common/diff/diffComputer.ts/LineSequence/constructor
class LineSequence:	constructor(lines: string[]) {
		const startColumns: number[] = [];
		const endColumns: number[] = [];
		for (let i = 0, length = lines.length; i < length; i++) {
			startColumns[i] = getFirstNonBlankColumn(lines[i], 1);
			endColumns[i] = getLastNonBlankColumn(lines[i], 1);
		}
		this.lines = lines;
		this._startColumns = startColumns;
		this._endColumns = endColumns;
	}