/**
* {@inheritDoc}
*/
public WizardStep getPreviousWizardStep(WizardStep step) {
WizardStep prev = null;
if (UpgradeWizardStep.FINISHED.equals(step)) {
prev = UpgradeWizardStep.PROGRESS;
} else if (UpgradeWizardStep.PROGRESS.equals(step)) {
prev = UpgradeWizardStep.REVIEW;
} else if (UpgradeWizardStep.REVIEW.equals(step)) {