var obj = {
  if: function (condition, trueStatement, falseStatement) {
    if (condition) return trueStatement;
    return falseStatment;
  },
  in: function () {
    console.log('This is an `in` method');
  },
  arguments: function () {
    console.log('This is an `arguments` method');
  },
  int: function () {
    console.log('This is an `int` method');
  }
};

obj.if(true, true, false);
obj.arguments();
obj.in();
obj.int();