code: function(options) {
        var mapping,
          models,
          defaultMapping = _.result(this, 'mapping'),
          defaultModels = _.result(this, 'models');
        mapping = options.mapping || defaultMapping;
        models = options.models || defaultModels;
        if (mapping) {
          this.setMappings(mapping, models);
        }
      }
docs: Sets the mapping using the form model's default mapping or the options.mappings if available.
  Also sets the tracked models if the form model's default models or the options.models is provided.
  @method __initMappings
  @param [options] {Object} See initialize options: 'mapping' and 'models'.
  @private