code: private void checkForCompletion() {
          final String methodName = "checkForCompletion(): ";
          // mark the list complete if that was the last awaited key
          if (actualIndices.isEmpty()) {
              if (tc.isDebugEnabled())
                  Tr.debug(tc, methodName + "setting state=COMPLETE");
              state = failedKeys == null
                              ? COMPLETE
                              : COMPLETE_WITH_FAILURES; // state change must be last action
          }
      }
docs: if all the keys have been satisfied or permanently failed, mark this list as being complete