code: public <A extends Annotation> A annotation(Class<A> annoCls) {
                  return f.getAnnotation(annoCls);
          }
docs: Returns this element's annotation for the specified type if such an
  annotation is present, else null.<br>
  Simply invokes {@link Field#getAnnotation(Class)}
  
  @param annoCls the Class object corresponding to the annotation type
  @return this element's annotation for the specified annotation type
  if present on this element, else null
  @see Field#getAnnotation(Class)