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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 _execute_single_level_task(self):
 """ Execute a single-level task """

        self.log(u"Executing single level task...")
        try:
            # load audio file, extract MFCCs from real wave, clear audio file
            self._step_begin(u"extract MFCC real wave")
            real_wave_mfcc = self._extract_mfcc(
                file_path=self.task.audio_file_path_absolute,
                file_format=None,
            )
            self._step_end()

            # compute head and/or tail and set it
            self._step_begin(u"compute head tail")
            (head_length, process_length, tail_length) = self._compute_head_process_tail(real_wave_mfcc)
            real_wave_mfcc.set_head_middle_tail(head_length, process_length, tail_length)
            self._step_end()

            # compute alignment, outputting a tree of time intervals
            self._set_synthesizer()
            sync_root = Tree()
            self._execute_inner(
                real_wave_mfcc,
                self.task.text_file,
                sync_root=sync_root,
                force_aba_auto=False,
                log=True,
                leaf_level=True
            )
            self._clear_cache_synthesizer()

            # create syncmap and add it to task
            self._step_begin(u"create sync map")
            self._create_sync_map(sync_root=sync_root)
            self._step_end()

            # log total
            self._step_total()
            self.log(u"Executing single level task... done")
        except Exception as exc:
            self._step_failure(exc)