code: def groupby(iterable, keyfunc):
      """Wrapper around ``itertools.groupby`` which sorts data first."""
      iterable = sorted(iterable, key=keyfunc)
      for key, group in itertools.groupby(iterable, keyfunc):
          yield key, group
  
file_path: espnet/egs/libri_css/asr1/local/get_perspeaker_output.py
imports: import argparse
  import itertools
  import os
  from collections import defaultdict
label_desc: Use image node_id 2 for calling a global function with example usage: groupby(iterable, keyfunc) without return types