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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 get_signed_query_params_v2(credentials, expiration, string_to_sign):
 """Gets query parameters for creating a signed URL. :type credentials: :class:`google.auth.credentials.Signing` :param credentials: The credentials used to create a private key for signing text. :type expiration: int or long :param expiration: When the signed URL should expire. :type string_to_sign: str :param string_to_sign: The string to be signed by the credentials. :raises: :exc:`AttributeError` if credentials is not an instance of :class:`google.auth.credentials.Signing`. :rtype: dict :returns: Query parameters matching the signing credentials with a signed payload. """

    ensure_signed_credentials(credentials)
    signature_bytes = credentials.sign_bytes(string_to_sign)
    signature = base64.b64encode(signature_bytes)
    service_account_name = credentials.signer_email
    return {
        "GoogleAccessId": service_account_name,
        "Expires": str(expiration),
        "Signature": signature,
    }