Prompting -- collect base classes that allows such input processing

[nicolay-r]

Something like that:

class PromptedSampleRowProvider(BaseSampleRowProvider):
    """
        Sample, enriched with the prompt technique.
    """

    def _fill_row_core(self, row, text_opinion_linkage, index_in_linked, etalon_label,
                       parsed_news, sentence_ind, s_ind, t_ind):

        row = super(PromptedSampleRowProvider, self)._fill_row_core(row=row,
                                                                    text_opinion_linkage=text_opinion_linkage,
                                                                    index_in_linked=index_in_linked,
                                                                    etalon_label=etalon_label,
                                                                    parsed_news=parsed_news,
                                                                    sentence_ind=sentence_ind,
                                                                    s_ind=s_ind,
                                                                    t_ind=t_ind)

        # TODO. Here is suppose to be a technique for row.

        return row