code: def write_sigmf(data_file, data, buffer=None, append=True):
      """
      Pack and write binary array to file, with SigMF spec.
  
      Parameters
      ----------
      file : str
          A string of filename to be read/unpacked to GPU.
      binary : ndarray
          Binary array to be written to file.
      buffer : ndarray, optional
          Pinned memory buffer to use when copying data from GPU.
      append : bool, optional
          Append to file if created.
  
      Returns
      -------
  
      """
  
      packed = pack_bin(data)
  
      write_bin(data_file, packed, buffer, append)
  
imports: import cupy
  from ._writer_cuda import _pack
label_desc: Use image node_id 3 for calling a global function with example usage: write_sigmf(data_file, data, buffer, append) without return types