问C#类设计问题，以使其单元可测试

EN

namespace SyncDemo
{
    public interface IProcessorA
    {
        void FunctionA(int a);
        void FunctionB(string b);
    }
    public interface IProcessorB
    {
        void FunctionA(int a);
        void FunctionB();
    }
    public interface IRepositoryA
    {
        void Add();
        void Delete();
    }
    public interface IRepositoryB
    {
        void Add();
        Void Delete();
    }

    public class ProcessorA : IProcessorA
    {
        private readonly IRepositoryA _repositoryA;

        public ProcessorA(IRepositoryA repositoryA)
        {
            _repositoryA = repositoryA;
        }

        public void FunctionA(int a)
        {
            //business logic work
            _repositoryA.Add();
        }

        public void FunctionB(string b)
        {
            _repositoryA.Delete();
        }
    }

    public class ProcessorB : IProcessorB
    {
        private readonly IRepositoryA _repositoryA;
        private readonly IRepositoryB _repositoryB;

        public ProcessorB(IRepositoryA repositoryA, IRepositoryB repositoryB)
        {
            _repositoryA = repositoryA;
            _repositoryB = repositoryB;
        }

        public void FunctionA(int a)
        {
            //do the same business logic work as in FunctionA in Class ProcessorA
            _repositoryA.Add();
        }

        public void FunctionB()
        {
            _repositoryB.Delete();
        }
    }

    public class RepositoryA : IRepositoryA
    {
        //this repository is responsible to talk with 'A' data source
        public void Add()
        {
            throw new NotImplementedException();
        }

        public void Delete()
        {
            throw new NotImplementedException();
        }
    }

    public class RepositoryB : IRepositoryB
    {
        //this repository is reponsible to talk with 'B' data source
        public void Add()
        {
            throw new NotImplementedException();
        }

        public void Delete()
        {
            throw new NotImplementedException();
        }
    }
}