public Map<String, String> getProtocolDataToAdvertise() {
        return handlers.entrySet().stream()
            .collect(Collectors.toMap(
                e -> e.getKey(),
                e -> e.getValue().getProtocolDataToAdvertise()
            ));
    }
@Test
    public void testGetProtocolDataToAdvertise() {
        String protocolData1 = "protocolData1";
        String protocolData2 = "protocolData2";
        when(handler1.getProtocolDataToAdvertise()).thenReturn(protocolData1);
        when(handler2.getProtocolDataToAdvertise()).thenReturn(protocolData2);

        Map<String, String> protocols = handlers.getProtocolDataToAdvertise();
        assertEquals(2, protocols.size());
        assertEquals(protocolData1, protocols.get(protocol1));
        assertEquals(protocolData2, protocols.get(protocol2));
    }