def tokenize_paragraphs(self):
        """Apply paragraph tokenization to this Text instance. Creates ``paragraphs`` layer."""
        tok = self.__paragraph_tokenizer
        spans = tok.span_tokenize(self.text)
        dicts = []
        for start, end in spans:
            dicts.append({'start': start, 'end': end})
        self[PARAGRAPHS] = dicts
        return self