docs: public static <T> T getElementValue(AnnotationMirror anno, CharSequence name, Class<T> expectedType, boolean useDefaults) {
          Map<? extends ExecutableElement, ? extends AnnotationValue> valmap
                  = useDefaults
                  ? getElementValuesWithDefaults(anno)
                  : anno.getElementValues();
  
  
          for (ExecutableElement elem : valmap.keySet()) {
              if (elem.getSimpleName().contentEquals(name)) {
                  AnnotationValue val = valmap.get(elem);
                  return expectedType.cast(val.getValue());
              }
          }
          return null;
      }