code: function(data) {
      for (var n in data) {
        if (data[n] instanceof Blob) {
          return true;
        }
        if ((angular.isObject(data[n]) || angular.isArray(data[n])) && hasFile(data[n])) {
          return true;
        }
      }
      return false;
    }
docs: Checks an object hash to see if it contains a File object, or, if legacy is true, checks to
  see if an object hash contains an <input type="file" /> element.