def a2b_hashed_base58(s):
    """
    If the passed string is hashed_base58, return the binary data.
    Otherwise raises an EncodingError.
    """
    data = a2b_base58(s)
    data, the_hash = data[:-4], data[-4:]
    if double_sha256(data)[:4] == the_hash:
        return data
    raise EncodingError("hashed base58 has bad checksum %s" % s)
If the passed string is hashed_base58, return the binary data.
    Otherwise raises an EncodingError.