old_contents: "use strict";
  
  const hasDebug = process.argv.indexOf("--debug") > -1;
  
  const debug = (!hasDebug) ? 
                      function() {} : 
                      (message) => console.log(message);
  
  debug.on = function() { return hasDebug; }
  
  module.exports = debug;
new_contents: "use strict";
  
  const hasDebug = process.argv.indexOf("--debug") > -1;
  
  const debug = (!hasDebug) ? 
                      function() {} : 
                      () => console.log.apply(console, arguments);
  
  debug.on = function() { return hasDebug; };
  
  module.exports = debug;
subject: Debug should output everything pls