Gets the credentials from a disclosed proof
        Example:
        msg_id = '1'
        phone_number = '8019119191'
        connection = await Connection.create(source_id)
        await connection.connect(phone_number)
        disclosed_proof = await DisclosedProof.create_with_msgid(source_id, connection, msg_id)
        creds = await disclosed_proof.get_creds()
        :return: credentials

async def get_creds(self) -> dict:
        """
        Gets the credentials from a disclosed proof
        Example:
        msg_id = '1'
        phone_number = '8019119191'
        connection = await Connection.create(source_id)
        await connection.connect(phone_number)
        disclosed_proof = await DisclosedProof.create_with_msgid(source_id, connection, msg_id)
        creds = await disclosed_proof.get_creds()
        :return: credentials
        """
        if not hasattr(DisclosedProof.get_creds, "cb"):
            self.logger.debug("vcx_disclosed_proof_retrieve_credentials: Creating callback")
            DisclosedProof.get_creds.cb = create_cb(CFUNCTYPE(None, c_uint32, c_uint32, c_char_p))

        c_disclosed_proof_handle = c_uint32(self.handle)

        data = await do_call('vcx_disclosed_proof_retrieve_credentials',
                             c_disclosed_proof_handle,
                             DisclosedProof.get_creds.cb)
        return json.loads(data.decode())