code: public Widget createAttributeWidget(Feature feature, AttributeDescriptor descriptor) {
  		Attribute<?> attribute = feature.getAttributes().get(descriptor.getName());
  
  		// Get a builder for the attribute
  		// attribute.getValue is e.g. StringAttribute, ImageURLAttribute, ...
  		AttributeWidgetBuilder builder = builders.get(attribute.getValue().getClass());
  		if (builder == null) {
  			builder = new DefaultAttributeWidgetBuilder();
  		}
  
  		// Build the widget and return it:
  		return builder.buildAttributeWidget(attribute.getValue());
  	}
docs: Create a widget for an attribute of a {@link Feature}.
  
  @param feature    the feature of the attribute.
  @param descriptor the descriptor of the attribute of the feature.
  @return the (possible custom) widget for a feature attribute.