void addItem(PropertyEditor.Item item){  
        final Node label = item.createLabel();        
        label.getStyleClass().add("property-label");
        GridPane.setValignment(label, VPos.TOP);
        GridPane.setHalignment(label, HPos.RIGHT);
        
        final Node editor = item.createEditor();
        editor.getStyleClass().add("property-editor");
        GridPane.setValignment(editor, VPos.CENTER);
        
        addRow(index.getAndIncrement(), label, editor);
        items.add(item);
    }
Adds a new editor item to the layout. New items are added at the
bottom.

@param item  the item
tool-parent/tool-propertyeditor/src/main/java/com/speedment/tool/propertyeditor/PropertyLayout.java