code: public AnnotationTypeElementDocImpl getAnnotationTypeElementDoc(
              MethodSymbol meth) {
  
          AnnotationTypeElementDocImpl result =
              (AnnotationTypeElementDocImpl)methodMap.get(meth);
          if (result != null) return result;
          result = new AnnotationTypeElementDocImpl(this, meth);
          methodMap.put(meth, result);
          return result;
      }
docs: Return the AnnotationTypeElementDoc for a MethodSymbol.
  Should be called only on symbols representing annotation type elements.