code: function (testFn) {
              var ancestor = this;
              while (ancestor.parentView) {
                  ancestor = ancestor.parentView;
                  if (ancestor && testFn(ancestor)) {
                      return ancestor;
                  }
              }
              return null;
          }
docs: Ascends up the ancestor line until an
  a test function returns true
  @param  {Function} testFn
  A function that returns a truthy
  value if the current ancestor should be
  returned
  @return {Backbone.BaseView|null}