Interfaces for Simple.Data + Impromptu

interfaces.cs

public interface IDatabase
{
    ICustomers Customers { get; }
    IEmployees Employees { get; }
}

public interface ICustomers
{
    ICustomer Get(int id);
    [UseNamedArgument]
    ICustomer Insert(string name = null, string location = null);
}

public interface IEmployees
{
    [UseNamedArgument]
    IEmployee Insert(string name = null, int employerId = 0);
}

public interface ICustomer
{
    int Id { get; set; }
    string Name { get; set; }
    string Location { get; set; }
    IList<IEmployee> Employees { get; } 
}

public interface IEmployee
{
    int Id { get; set; }
    int EmployerId { get; set; }
    ICustomer Employer { get; }
    string Name { get; set; }
}