'fit_transform.
Learn the vocabulary dictionary and return indexies of words.
Arguments:
raw_documents: An iterable which yield either str or unicode.
unused_y: to match fit_transform signature of estimators.
Returns:
X: iterable, [n_samples, max_document_length] Word-id matrix.'

def fit_transform(self, raw_documents, unused_y=None):

    return super(VocabularyProcessor, self).fit_transform(raw_documents, unused_y)
