tds/src/main/java/thredds/featurecollection/InvDatasetFeatureCollection.java
protected State checkState() throws IOException {
    State localState;

    synchronized (lock) {
      if (first) {
        firstInit();
        updateCollection(state, config.updateConfig.updateType);
        // makeDatasetTop(state);
        first = false;
      }
      localState = state.copy();
    }

    return localState;
  }
protected State checkState() throws IOException {
    State localState;

    synchronized (lock) {
      if (first) {
        firstInit();
        updateCollection(state, config.updateConfig.updateType);
        // makeDatasetTop(state);
        first = false;
      }
      localState = state.copy();
    }

    return localState;
  }
A request has come in, check that the state has been initialized.
this is called from the request thread.

@return a copy of the State