code: def _move_file_with_sizecheck(tx_file, final_file):
      
  
      #logger.debug("Moving %s to %s" % (tx_file, final_file))
  
      tmp_file = final_file + ".bcbiotmp"
      open(tmp_file, 'wb').close()
  
      want_size = utils.get_size(tx_file)
      shutil.move(tx_file, final_file)
      transfer_size = utils.get_size(final_file)
  
      assert want_size == transfer_size, (
          'distributed.transaction.file_transaction: File copy error: '
          'file or directory on temporary storage ({}) size {} bytes '
          'does not equal size of file or directory after transfer to '
          'shared storage ({}) size {} bytes'.format(
              tx_file, want_size, final_file, transfer_size)
      )
      utils.remove_safe(tmp_file)
docs: Move transaction file to final location,
         with size checks avoiding failed transfers.
  
         Creates an empty file with '.bcbiotmp' extention in the destination
         location, which serves as a flag. If a file like that is present,
         it means that transaction didn't finish successfully.