def METHOD_NAME(instr, outfile):
    r"""
    Decode a base64-encoded string and write the result to a file
    .. versionadded:: 2016.3.0
    CLI Example:
    .. code-block:: bash
        salt '*' hashutil.base64_decodefile instr='Z2V0IHNhbHRlZAo=' outfile='/path/to/binary_file'
    """
    encoded_f = io.StringIO(instr)
    with salt.utils.files.fopen(outfile, "wb") as f:
        base64.decode(encoded_f, f)
    return True