code: private static int findIndexOfValue(final Method method) {
          int index = 0;
          for (Annotation[] annotations : method.getParameterAnnotations()) {
              for (Annotation a : annotations) {
                  if (XBValue.class.equals(a.annotationType())) {
                      return index;
                  }
              }
              ++index;
          }
          return 0; // If no attribute is annotated, the first one is taken.
      }
docs: Setter projection methods may have multiple parameters. One of them may be annotated with
  {@link XBValue} to select it as value to be set.
  
  @param method
  @return index of fist parameter annotated with {@link XBValue} annotation.