text: #!/usr/bin/env node
  
  `use strict`;
  
  function echo(input) {
      console.log('echo() function is invoked with argument "%s"', input || "[EMPTY]");
      return input;
  }
  
  function helloWorld() {
      console.log('helloWorld() function is invoked');
      return "Hello, World!";
  }
  
  module.exports = {
      echo,
      helloWorld
  };
    