code: def _process_crf(process_tuple):
      """
      Extract the best beat sequence for a piece.
  
      This proxy function is necessary to process different intervals in parallel
      using the multiprocessing module.
  
      Parameters
      ----------
      process_tuple : tuple
          Tuple with (activations, dominant_interval, allowed deviation from the
          dominant interval per beat).
  
      Returns
      -------
      beats : numpy array
          Extracted beat positions [frames].
      log_prob : float
          Log probability of the beat sequence.
  
      """
      # pylint: disable=no-name-in-module
      from .beats_crf import best_sequence
  
      # activations, dominant_interval, interval_sigma = process_tuple
      return best_sequence(*process_tuple)
  
imports: from __future__ import absolute_import, division, print_function
  import sys
  import numpy
  from ..audio.signal import signal_frame, smooth
  from ..ml.nn import average_predictions
  from ..processors import OnlineProcessor, ParallelProcessor, Processor, SequentialProcessor
label_desc: Use image node_id 3 for calling a global function with example usage: _process_crf(process_tuple) and returns: best_sequence