### Question:
LinkFormatCodec implements ContentCodec { @Override public byte[] valueToBytes(Object value, Map<String, String> parameters) { if (value instanceof Map) { Map<String, Map<String, String>> valueMap = (Map<String, Map<String, String>>) value; String bodyString = valueMap.entrySet().stream().map(e -> e.getKey() + ";" + e.getValue().entrySet().stream().map(e2 -> e2.getKey() + "=\"" + e2.getValue() + "\"").collect(joining(";"))).collect(joining(",")); return bodyString.getBytes(); } else { log.warn("Unable to serialize non-map value: {}", value); return new byte[0]; } }  @Override String getMediaType(); @Override T bytesToValue(byte[] body,
                              DataSchema<T> schema,
                              Map<String, String> parameters); @Override byte[] valueToBytes(Object value, Map<String, String> parameters);  }### Answer:
@Test public void valueToBytes() throws ContentCodecException { Map<String, Map<String, String>> value = Map.of( "</reg/1/>", Map.of( "ep", "RIOT-34136DAB556DC1D3", "base", "coap: "rt", "core.rd-ep" ), "</reg/2/>", Map.of( "ep", "RIOT-34136EAB746DC1D3", "base", "coap: "rt", "core.rd-ep" ) ); byte[] bytes = codec.valueToBytes(value); assertTrue(true); }