public static Set<String> plainProtocolSet(
        JoinGroupRequestProtocolCollection supportedProtocols
    ) {
        Set<String> protocolNames = new HashSet<>();
        for (JoinGroupRequestProtocol protocol : supportedProtocols) {
            protocolNames.add(protocol.name());
        }
        return protocolNames;
    }
@Test
    public void testPlainProtocolSet() {
        JoinGroupRequestProtocolCollection protocolCollection =
            new JoinGroupRequestProtocolCollection();

        protocolCollection.add(new JoinGroupRequestProtocol()
            .setName("range").setMetadata(new byte[]{0}));
        protocolCollection.add(new JoinGroupRequestProtocol()
            .setName("roundrobin").setMetadata(new byte[]{1}));

        Set<String> expectedProtocolNames = new HashSet<>();
        expectedProtocolNames.add("range");
        expectedProtocolNames.add("roundrobin");

        assertEquals(expectedProtocolNames, ClassicGroupMember.plainProtocolSet(protocolCollection));
    }