'Call transform on the estimator with the best found parameters.
Only available if the underlying estimator supports ``transform`` and
``refit=True``.
Parameters
X : indexable, length n_samples
Must fulfill the input assumptions of the
underlying estimator.'

@if_delegate_has_method(delegate=('best_estimator_', 'estimator'))
def transform(self, X):

    self._check_is_fitted('transform')
    return self.best_estimator_.transform(X)
