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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 verify_raw_data(raw_data, pubkey_hex, sigb64):
 """ Verify the signature over a string, given the public key and base64-encode signature. Return True on success. Return False on error. """

    if not isinstance(raw_data, (str, unicode)):
        raise ValueError("data is not a string")

    raw_data = str(raw_data)

    vi = ECVerifier(pubkey_hex, sigb64)
    vi.update(raw_data)
    return vi.verify()