[Dart] - Flutter issue with generic classes

Description

I am using a standard aspnet boilerplate (AspNet Core 2.1). I'm trying to generate flutter code however I run into issues with generic types.

One of the C# functions is declared as following:

Task<ListResultDto<PermissionDto>> GetAllPermissions();

Full Gist with Declarations:
https://gist.github.com/antonio-mikulic/7a0c5e50e01bf9e3e0c1d5c7ef535e2f

And this is part of genenerated code:

class ListResultDto[PermissionDto] { 
  List<PermissionDto> items = []; 
  ListResultDto[PermissionDto]();
}
class PermissionDto {
  String name = null;
  String displayName = null;
  String description = null;
  int id = null;
  PermissionDto();

  static List<PermissionDto> listFromJson(List<dynamic> json) {
    return json == null ? new List<PermissionDto>() : json.map((value) => new PermissionDto.fromJson(value)).toList();
  }
}

1. Error: Occurs on PermissionDto class: "The name 'PermissionDto' is already defined.dart(duplicate_definition)".

2. Error: PermissionDto(); Invalid constructor name.dart(invalid_constructor_name)
   Errors 1 and 2 go away after class ListResultDto[PermissionDto] {} is changed into ListResultDtoPermissionDto.

3. Error: Occurs on class ListResultDto[PermissionDto] {}. No other errors in this file.

Expected to find ';'.dart(expected_token)
Variables must be declared using the keywords 'const', 'final', 'var' or a type name.dart(missing_const_final_var_or_type)
dynamic PermissionDto
swagger.api

Swagger-codegen version

2.4.1-SNAPSHOT

Command line used for generation

set executable=..\..\modules\swagger-codegen-cli\target\swagger-codegen-cli.jar
If Not Exist %executable% (
  mvn clean package
)
REM set JAVA_OPTS=%JAVA_OPTS% -Xmx1024M
set ags=generate -i http://localhost:21021/swagger/v1/swagger.json -l dart -o swagger -DbrowserClient=false -DdateLibrary=joda -DhideGenerationTimestamp=true

java %JAVA_OPTS% -jar %executable% %ags%

Steps to reproduce

Generate code from empty aspnet boilerplate.

Start from the swagger-codegen CLI Dart generation entry point and reproduce the issue with the provided ASP.NET Swagger URL or gist declarations. Inspect the generated ListResultDto[PermissionDto] and PermissionDto output, then verify that generated Dart parses without duplicate-definition, invalid-constructor-name, or expected-token errors.