<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def open_file_for_write(filepath, mode=None):
 """Writes both to given filepath, and tmpdir location. This is to get around the problem with some NFS's where immediately reading a file that has just been written is problematic. Instead, any files that we write, we also write to /tmp, and reads of these files are redirected there. Args: filepath (str):
 File to write. mode (int):
 Same mode arg as you would pass to `os.chmod`. Yields: File-like object. """

    stream = StringIO()
    yield stream
    content = stream.getvalue()

    filepath = os.path.realpath(filepath)
    tmpdir = tmpdir_manager.mkdtemp()
    cache_filepath = os.path.join(tmpdir, os.path.basename(filepath))

    debug_print("Writing to %s (local cache of %s)", cache_filepath, filepath)

    with atomic_write(filepath, overwrite=True) as f:
        f.write(content)

    if mode is not None:
        os.chmod(filepath, mode)

    with open(cache_filepath, 'w') as f:
        f.write(content)

    file_cache[filepath] = cache_filepath