code: public Set<String> getProperties() {
  		Set<String> allProperties = new HashSet<>();
  		for (PropertiesCoreExtension<T, ?, ?, ?> properties : propertiesMap
  				.values()) {
  			allProperties.addAll(properties.getProperties());
  		}
  		return allProperties;
  	}
docs: Get the unique properties
  
  @return set of properties