docs: private static void appendToBuilder(UriComponentsBuilder builder, TemplateVariable variable, @Nullable Object value) {
  
  		if (value == null) {
  
  			if (variable.isRequired()) {
  				throw new IllegalArgumentException(
  						String.format("Template variable %s is required but no value was given!", variable.getName()));
  			}
  
  			return;
  		}
  
  		switch (variable.getType()) {
  			case COMPOSITE_PARAM:
  				appendComposite(builder, variable.getName(), value);
  				break;
  			case REQUEST_PARAM:
  			case REQUEST_PARAM_CONTINUED:
  				builder.queryParam(variable.getName(), value);
  				break;
  			case PATH_VARIABLE:
  			case SEGMENT:
  				builder.pathSegment(value.toString());
  				break;
  			case FRAGMENT:
  				builder.fragment(value.toString());
  				break;
  		}
  	}