docstr: Gets called when a stage (either training, validation, test) starts.
docstr_tok: ["Gets","called","when","a","stage","(","either","training",",","validation",",","test",")","starts","."]
code: def on_stage_start(self, stage, epoch=None):
      "Gets called when a stage (either training, validation, test) starts."
      self.binary_metrics = sb.utils.metric_stats.BinaryMetricStats()
  
file_path: speechbrain/tests/integration/VAD/example_vad.py
imports: import os
  import torch
  import numpy
  import speechbrain
  from hyperpyyaml import load_hyperpyyaml
label_desc: Use image node_id 3 for calling the VADBrain obj's underlying member method code with example usage: obj.on_stage_start(stage, epoch) without return types