code: def _execute_single_level_task(self):
          
          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)
docs: Execute a single-level task