code: public boolean hasElementWithKey(String key) {
  
          for (CmsContainerConfiguration configuration : m_parentConfigurations) {
              if (configuration.getNewElements().containsKey(key)) {
                  return true;
              }
          }
          return false;
      }
docs: Checks whether an element with the given key is actually defined in this inherited container state.<p>
  
  @param key the key for which the check should be performed
  
  @return true if an element with the key has been defined in this state