src/vs/workbench/contrib/mergeEditor/browser/model/modifiedBaseRange.ts/ModifiedBaseRangeState/toString
class ModifiedBaseRangeState:	public toString(): string {
		const arr: ('1' | '2')[] = [];
		if (this.input1) {
			arr.push('1');
		}
		if (this.input2) {
			arr.push('2');
		}
		if (this.input2First) {
			arr.reverse();
		}
		return arr.join(',');
	}