class_docstr: Metrics for MIDI heuristic.
class_docstr_tok: ["Metrics","for","MIDI","heuristic","."]
code: def __init__(self, sample_rate, frame_rate):
      super().__init__(sample_rate, frame_rate)
      self._midi_metrics = metrics.MidiMetrics(
          tag="heuristic", frames_per_second=frame_rate
      )
  
imports: import ddsp
  from ddsp.training import heuristics
  from ddsp.training import metrics
  from ddsp.training import summaries
  import gin
  import numpy
  import tensorflow.compat.v2
label_desc: Use image node_id 1 to create a new MidiHeuristicEvaluator object from inherited base classes: BaseEvaluator with example: obj = MidiHeuristicEvaluator(sample_rate, frame_rate)