Source generator: Get actual type for FieldElement

So I've been playing around with code generation in Dart, and I have a problem resolving Element type in "data" classes. I have 2 data classes, and 2nd one has a type of a 1st one defined as a field.

first.dart:

part 'first.g.dart';

@Data(name="First")
class _First {
}

second.dart:

import 'first.dart';
part 'second.g.dart';

@Data(name="Second")
class _Second {
    First first;
}

You might have noticed, that _Second has field First instead of _First. That's because I generate two new classes. These two new classes contain additional functionality, like generated hashCode and some other custom methods I need.

In my Generator class, I need to obtain type string of field first. I'm doing this by fieldElement.type?.getDisplayString(). This works fine for all other non-generated classes, like num for example. But in case of first field, returned type string is "dynamic".

Is there a way to obtain correct type? Should "First" in this case.

data_generator.dart

class Data extends GeneratorForAnnotation<Data> {
    @override 
    generateForAnnotatedElement(Element element, ConstantReader annotation,
            BuildStep buildStep) {
        if(element is ClassElement) {
            FieldElement element = findField();
            String type = element.type?.getDisplayString();
            assert(type != "dynamic");
            //...
        }
    }
    //...
}