### Question:
MongoDbPageTemplateConverter implements HydratingModelConverter<PageTemplate, MongoDbPageTemplate> { @Override public void hydrate(MongoDbPageTemplate dehydrated) { if (dehydrated == null) { return; } dehydrated.setPageLayoutRepository(pageLayoutRepository); for (PageTemplateRegion region : dehydrated.getPageTemplateRegions()) { region.setPageTemplate(dehydrated); for (PageTemplateWidget widget : region.getPageTemplateWidgets()) { widget.setPageTemplateRegion(region); } } if (dehydrated.getSubPageTemplates() != null) { for (PageTemplate sub : dehydrated.getSubPageTemplates()) { sub.setParentPageTemplate(dehydrated); hydrate((MongoDbPageTemplate) sub); } } }  @Override void hydrate(MongoDbPageTemplate dehydrated); @Override Class<PageTemplate> getSourceType(); @Override MongoDbPageTemplate convert(PageTemplate source); void setPageLayoutRepository(PageLayoutRepository pageLayoutRepository); PageLayoutRepository getPageLayoutRepository();  }### Answer:
@Test public void hydrate_Null(){ pageTemplateConverter.hydrate(null); assertThat(true, is(true)); }