text: function addTogether(x) {
      var args = arguments;
  
      function numOrWhat(x) {
          if (Number.isInteger(x) === false) {
              return undefined;
          } else
          return x;
      }
  
      if (arguments.length > 1) {
          var a = numOrWhat(arguments[0]);
          var b = numOrWhat(arguments[1]);
          if (a === undefined || b === undefined) {
              return undefined;
          } else
          return a + b;
      } else
      var c = arguments[0];
      if (numOrWhat(c)) {
          return function(missingArg) {
              if (c === undefined || numOrWhat(missingArg) === undefined) {
                  return undefined;
              } else
              return c + missingArg;
          };
      }
  }
  
  console.log('answer: ', addTogether(2));
  