docs: public BaseMethodBinding<?> getBinding(RestOperationTypeEnum operationType, String theBindingKey) {
          String bindingKey = StringUtils.defaultIfBlank(theBindingKey, DEFAULT_METHOD_KEY);
  		ConcurrentHashMap<String, BaseMethodBinding<?>> map = getMapForOperation(operationType);
          if(map == null || !map.containsKey(bindingKey)) {
              throw new NotImplementedOperationException("Operation not implemented");
          }  else {
              return map.get(bindingKey);
          }
      }