code: def _write_module_descriptor_file(handle, module_dir):
    
    readme = _module_descriptor_file(module_dir)
    readme_content = (
        "Module: %s\nDownload Time: %s\nDownloader Hostname: %s (PID:%d)" %
        (handle, str(datetime.datetime.today()), socket.gethostname(),
         os.getpid()))
    # The descriptor file has no semantic meaning so we allow 'overwrite' since
    # there is a chance that another process might have written the file (and
    # crashed), we just overwrite it.
    tf_utils.atomic_write_string_to_file(readme, readme_content, overwrite=True)
docs: Writes a descriptor file about the directory containing a module.
  
    Args:
      handle: Module name/handle.
      module_dir: Directory where a module was downloaded.