code: @SuppressWarnings("unchecked")
      public static Map<String, List<Object[]>> getDebugInfoMap(String clientId)
      {
          final Map<String, Object> requestMap = FacesContext.getCurrentInstance()
                  .getExternalContext().getRequestMap();
          Map<String, List<Object[]>> debugInfo = (Map<String, List<Object[]>>) 
                  requestMap.get(ErrorPageWriter.DEBUG_INFO_KEY + clientId);
          if (debugInfo == null)
          {
              // no debug info available yet, create one and put it on the attributes map
              debugInfo = new HashMap<String, List<Object[]>>();
              requestMap.put(ErrorPageWriter.DEBUG_INFO_KEY + clientId, debugInfo);
          }
          return debugInfo;
      }
docs: Returns the debug-info Map for the given component.
  ATTENTION: this method is duplicate in UIInput.
  @param clientId
  @return