Constructs string of all documents.

            :return: document representation of the dataset, one line per document
            :rtype: str

def wordify(self):
        """
        Constructs string of all documents.

            :return: document representation of the dataset, one line per document
            :rtype: str
        """
        string_documents = []
        for klass, document in zip(self.resulting_classes, self.resulting_documents):
            string_documents.append("!" + str(klass) + " " + '' .join(document))
        return '\n'.join(string_documents)