src/vs/workbench/api/common/extHostTypes.ts/Position/of
class Position:	static of(obj: vscode.Position): Position {
		if (obj instanceof Position) {
			return obj;
		} else if (this.isPosition(obj)) {
			return new Position(obj.line, obj.character);
		}
		throw new Error('Invalid argument, is NOT a position-like object');
	}