text: function UserException(message) {
      'use strict';
      this.message = message;
      this.name = "UserException";
  }
  
  function add() {
      'use strict';
      if (arguments.length === 2) {
          return arguments[0] + arguments[1];
      } else if (arguments.length === 1) {
          return arguments[0] * 2;
      } else {
          throw new UserException('You must pass in either one or two parameters.');
      }
  }
  
  
  const adder = (...fatArguments) => {
      console.log('FAT ARGUMENTS', fatArguments);
      if (fatArguments.length === 2) {
          return fatArguments[0] + fatArguments[1];
      } else if (fatArguments.length === 1) {
          return fatArguments[0] * 2;
      } else {
          throw new UserException('You must pass in either one or two parameters.');
      }
  };
  
  console.log(add(2));
  console.log(add(2, 3));
  try {
      console.log(add());
  } catch(userException) {
      console.log(userException)
  }
  
  console.log('\n<-------------->\n<-------------->\n');
  
  console.log(adder(2));
  console.log(adder(2, 3));
  try {
      console.log(adder());
  } catch(userException) {
      console.log(userException)
  }
  
  
  
  
  