code: protected ReadOnlyListWrapper<PathElementType> innerTypesProperty() {
  		if (this.types == null) {
  			this.types = new ReadOnlyListWrapper<>(this, MathFXAttributeNames.TYPES,
  					FXCollections.observableList(new ArrayList<>()));
  		}
  		return this.types;
  	}
docs: Replies the private types property.
  
  @return the private types property.