Example from Karl

Karl's first example

public class UserRepository
{
  private readonly IDataStore _store;
  private readonly IEncryption _encryption;
   
  public UserRepository(IDataStore store, IEncryption encryption)
  {
    _store = store;
    _encryption = encryption;
  }
   
  public User FindByCredentials(string username, string password)
  {
    var user = _store.FindOneByNamedQuery("FindUserByUserName", username);
    if (user == null) { return null; }
    return _encryption.CheckPassword(user.Password, password) ? user : null;
  }
}