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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _file_md5(file_):
 """ Compute the md5 digest of a file in base64 encoding. """

    md5 = hashlib.md5()
    chunk_size = 128 * md5.block_size
    for chunk in iter(lambda: file_.read(chunk_size), b''):
        md5.update(chunk)
    file_.seek(0)
    byte_digest = md5.digest()
    return base64.b64encode(byte_digest).decode()