public boolean hasPendingState() {
        return pendingState != null;
    }
Check whether or not there is a pending state. If there is a pending
state, views might skip DOM updates and wait for the new data to be
rendered when the pending state is resolved.

@return true if there is a pending state, false if not
stroom-core-client-widget/src/main/java/com/google/gwt/user/cellview/client/HasDataPresenter.java