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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _append_trivial_tree(self, text_file, sync_root):
 """ Append trivial tree, made by one HEAD, one sync map fragment for each element of ``text_file``, and one TAIL. This function is called if either ``text_file`` has only one element, or if ``sync_root.value`` is an interval with zero length (i.e., ``sync_root.value.begin == sync_root.value.end``). """

        interval = sync_root.value
        #
        # NOTE the following is correct, but it is a bit obscure
        # time_values = [interval.begin] * (1 + len(text_file)) + [interval.end] * 2
        #
        if len(text_file) == 1:
            time_values = [interval.begin, interval.begin, interval.end, interval.end]
        else:
            # interval.begin == interval.end
            time_values = [interval.begin] * (3 + len(text_file))
        aba = AdjustBoundaryAlgorithm(rconf=self.rconf, logger=self.logger)
        aba.intervals_to_fragment_list(
            text_file=text_file,
            time_values=time_values
        )
        aba.append_fragment_list_to_sync_root(sync_root=sync_root)