code:     protected Collection<String> getStandardAttributes() {
          Class clz = getClass();
          Collection<String> standardAttributes = standardAttributesMap.get(clz);
          if (standardAttributes == null) {
              Collection<Method> methods = AnnotationUtils.getAnnotatedMethods(clz, StrutsTagAttribute.class);
              standardAttributes = new HashSet<>(methods.size());
              for(Method m : methods) {
                  standardAttributes.add(StringUtils.uncapitalize(m.getName().substring(3)));
              }
              standardAttributesMap.putIfAbsent(clz, standardAttributes);
          }
          return standardAttributes;
      }
  
  