code: function (cb) {
          return function() {
              var args = Array.prototype.slice.call(arguments);
              var next = args.pop();
  
              args.push(function() {
                  // if (err) return next(err);
                  var iargs = Array.prototype.slice.call(arguments);
  
                  next.apply(this, iargs);
              });
              cb.apply(this, args);
          };
      }
docs: wrap a function that has a signature of ([arg1], [arg2], ...[argn], callback) where callback has a signature of (err, [arg1], [arg2], ... [argn]) example: api.wrap(require('fs').readFile)