code: def _sign_model(fout):
      """
      Write signature of the file in Facebook's native fastText `.bin` format
      to the binary output stream `fout`. Signature includes magic bytes and version.
  
      Name mimics original C++ implementation, see
      [FastText::signModel](https://github.com/facebookresearch/fastText/blob/master/src/fasttext.cc)
  
      Parameters
      ----------
      fout: writeable binary stream
      """
      fout.write(_FASTTEXT_FILEFORMAT_MAGIC.tobytes())
      fout.write(_FASTTEXT_VERSION.tobytes())
  
imports: import collections
  import gzip
  import io
  import logging
  import struct
  import numpy
label_desc: Use image node_id 9 for calling a global function with example usage: _sign_model(fout) without return types