merge method
Creates a new TModel where each properties from this object has been merged with the matching properties from the other object.
For example:
var myModel3 = myModel1.merge(myModel2);
Implementation
@override
FastCategory merge(covariant FastCategory category) {
return copyWith(
labelText: category.labelText,
valueText: category.valueText,
weight: category.weight,
);
}