[Mapper]
public interface IProductMapper
{
    ProductDTO Map(Product customer);
}

[Mapper]
public interface ICustomerMapper
{
    //for queryable
    Expression<Func<Customer, CustomerDTO>> ProjectToDto { get; }
    
    //map from POCO to DTO
    CustomerDTO MapToDto(Customer customer);
    //map to existing object
    Customer MapToExisting(CustomerDTO dto, Customer customer);
}

public class MyRegister : IRegister
{
    public void Register(TypeAdapterConfig config)
    {
        config.NewConfig<TSource, TDestination>();
    }
}