When creating an ILcdModel for a single WMTS layer, you can skip the creation of a TLcdWMTSDataSource by specifying the needed layer directly in the server URL: 

String serverURL = "https://sampleservices.luciad.com/wmts";
String layerName = "4ceea49c-3e7c-4e2d-973d-c608fb2fb07e";

//Concat the url and layer name to a single string
String sourceName = String.format("%s?data=%s", serverURL, layerName);

//Decode the model
ILcdModelDecoder decoder = new TLcdWMTSModelDecoder();
ILcdModel model = decoder.decode(sourceName);

is the equivalent of

String serverURL = "https://sampleservices.luciad.com/wmts";
String layerName = "4ceea49c-3e7c-4e2d-973d-c608fb2fb07e";

//Create the data source
TLcdWMTSDataSource dataSource = TLcdWMTSDataSource.newBuilder()
                                                  .uri(serverURL)
                                                  .layer(layerName)
                                                  .build();

//Decode the model
ILcdModelDecoder decoder = new TLcdWMTSModelDecoder();
ILcdModel model = decoder.decodeSource(dataSource);