src/vs/base/common/diff/diff.ts/LcsDiff/_boundaryScore
class LcsDiff:	private _boundaryScore(originalStart: number, originalLength: number, modifiedStart: number, modifiedLength: number): number {
		const originalScore = (this._OriginalRegionIsBoundary(originalStart, originalLength) ? 1 : 0);
		const modifiedScore = (this._ModifiedRegionIsBoundary(modifiedStart, modifiedLength) ? 1 : 0);
		return (originalScore + modifiedScore);
	}