@Override
            public void execute() {
                // Verify that this command was the last one scheduled.
                if (pendingStateCommand == this) {
                    resolvePendingState(null);
                }
            }
Ensure that a pending {@link DefaultState} exists and return it.

@return the pending state
stroom-core-client-widget/src/main/java/com/google/gwt/user/cellview/client/HasDataPresenter.java