class_docstr: The GzipFile class simulates most of the methods of a file object with
  the exception of the truncate() method.
  
  This class only supports opening files in binary mode. If you need to open a
  compressed file in text mode, use the gzip.open() function.
code: def flush(self, zlib_mode=zlib.Z_SYNC_FLUSH):
      self._check_not_closed()
      if self.mode == WRITE:
          # Ensure the compressor's buffer is flushed
          self.fileobj.write(self.compress.flush(zlib_mode))
          self.fileobj.flush()
  
imports: import struct, sys, time, os
  import zlib
  import builtins
  import io
  import _compression
label_desc: Use image node_id 13 for calling the GzipFile obj's underlying member method code with example usage: obj.flush(zlib_mode) without return types