class_docstr: Metrics for MIDI heuristic.
class_docstr_tok: ["Metrics","for","MIDI","heuristic","."]
code: def evaluate(self, batch, outputs, losses):
      del losses  # Unused.
      notes = self._compute_heuristic_notes(outputs)
      self._midi_metrics.update_state(outputs, notes)
  
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 3 for calling the MidiHeuristicEvaluator obj's underlying member method code with example usage: obj.evaluate(batch, outputs, losses) without return types