code: public AnnotatedTypeBuilder<X> addToMethodParameter(Method method, int position, Annotation annotation) {
         if (!methods.containsKey(method)) {
             methods.put(method, new AnnotationBuilder());
         }
         if (methodParameters.get(method) == null) {
             methodParameters.put(method, new HashMap<Integer, AnnotationBuilder>());
         }
         if (methodParameters.get(method).get(position) == null) {
             methodParameters.get(method).put(position, new AnnotationBuilder());
         }
         methodParameters.get(method).get(position).add(annotation);
         return this;
     }
docs: Add an annotation to the specified method parameter. If the method is not
  already present, it will be added. If the method parameter is not already
  present, it will be added.
  
  @param method     the method to add the annotation to
  @param position   the position of the parameter to add
  @param annotation the annotation to add
  @throws IllegalArgumentException if the annotation is null