How to use the webauthn.const.USER_PRESENT function in webauthn

# NOTE: In Python 3, `auth_data_rp_id_hash` will be bytes,
            # which is expected in `_verify_rp_id_hash()`.
            if not _verify_rp_id_hash(auth_data_rp_id_hash, self.rp_id):
                raise RegistrationRejectedException(
                    'Unable to verify RP ID hash.')

            # Step 10.
            #
            # Verify that the User Present bit of the flags in authData
            # is set.

            # Authenticator data flags.
            # https://www.w3.org/TR/webauthn/#authenticator-data
            flags = struct.unpack('!B', auth_data[32:33])[0]

            if (flags & const.USER_PRESENT) != 0x01:
                raise RegistrationRejectedException(
                    'Malformed request received.')

            # Step 11.
            #
            # If user verification is required for this registration, verify
            # that the User Verified bit of the flags in authData is set.
            if (self.uv_required and (flags & const.USER_VERIFIED) != 0x04):
                raise RegistrationRejectedException(
                    'Malformed request received.')

            # Step 12.
            #
            # Verify that the values of the client extension outputs in
            # clientExtensionResults and the authenticator extension outputs
            # in the extensions in authData are as expected, considering the