src/vs/workbench/contrib/mergeEditor/browser/model/modifiedBaseRange.ts/ModifiedBaseRangeState/withInput1
class ModifiedBaseRangeState:	public withInput1(value: boolean): ModifiedBaseRangeState {
		return new ModifiedBaseRangeState(
			value,
			this.input2,
			value !== this.input2 ? this.input2 : this.input2First,
			false
		);
	}