code: def _gzip(bs):
      out = io.BytesIO()
      with gzip.GzipFile(fileobj=out, mode="wb") as f:
          f.write(bs)
      return out.getvalue()
  
imports: import gzip
  import io
  import struct
  from unittest import mock
  from werkzeug import test
  from werkzeug import wrappers
  from tensorboard import test
  from tensorboard.backend import http_util
label_desc: Use image node_id 1 for calling a global function with example usage: _gzip(bs) and returns: out