docs: public static String getImplementedTargetNamespace(ClassInfo classInfo) {
          String defaultValue = getNamespace(classInfo, null);
          if (StringUtils.isEmpty(defaultValue)) {
              defaultValue = JaxWsConstants.UNKNOWN_NAMESPACE;
          }
  
          AnnotationInfo annotationInfo = getAnnotationInfoFromClass(classInfo, JaxWsConstants.TARGETNAMESPACE_ATTRIBUTE);
          if (annotationInfo == null) {
              return "";
          }
  
          AnnotationValue attrValue = annotationInfo.getValue(JaxWsConstants.TARGETNAMESPACE_ATTRIBUTE);
          String attrFromAnnotation = attrValue == null ? null : attrValue.getStringValue().trim();
          return StringUtils.isEmpty(attrFromAnnotation) ? defaultValue : attrFromAnnotation;
      }