src/vs/workbench/api/common/extHostTypes.ts/Position/translate
class Position:	translate(lineDeltaOrChange: number | undefined | { lineDelta?: number; characterDelta?: number }, characterDelta: number = 0): Position {

		if (lineDeltaOrChange === null || characterDelta === null) {
			throw illegalArgument();
		}

		let lineDelta: number;
		if (typeof lineDeltaOrChange === 'undefined') {
			lineDelta = 0;
		} else if (typeof lineDeltaOrChange === 'number') {
			lineDelta = lineDeltaOrChange;
		} else {
			lineDelta = typeof lineDeltaOrChange.lineDelta === 'number' ? lineDeltaOrChange.lineDelta : 0;
			characterDelta = typeof lineDeltaOrChange.characterDelta === 'number' ? lineDeltaOrChange.characterDelta : 0;
		}

		if (lineDelta === 0 && characterDelta === 0) {
			return this;
		}
		return new Position(this.line + lineDelta, this.character + characterDelta);
	}