using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var requests = new List<RequestDtoBase>();

        var remoteServiceFacade = new RemoteServiceFacade();

        remoteServiceFacade.CallAlpha(requests.OfType<AlphaRequestDto>());

        remoteServiceFacade.CallBeta(requests.OfType<BetaRequestDto>());

    }

}

​

internal class RemoteServiceFacade {

    public IEnumerable<ResponseDto> CallAlpha(IEnumerable<AlphaRequestDto> requests) {

        return Array.Empty<ResponseDto>();

    }

    public IEnumerable<ResponseDto> CallBeta(IEnumerable<BetaRequestDto> requests) {

        return Array.Empty<ResponseDto>();

    }

}

​

internal abstract class RequestDtoBase { }

​

internal class AlphaRequestDto : RequestDtoBase { }

​

internal class BetaRequestDto : RequestDtoBase { }

​

internal class ResponseDto { }

​