Design and Architecture

public interface IRepository<TEntity> where TEntity : class
{
    TEntity Get(int id);
    IEnumerable<TEntity> GetAll();
    IEnumerable<TEntity> Find(Expression<Func<TEntity, bool>> predicate);

    void Add(TEntity entity);
    void AddRange(IEnumerable<TEntity> entities);

    void Remove(TEntity entity);
    void RemoveRange(IEnumerable<TEntity> entities);
}

public class UnitOfWork : IUnitOfWork
{
    private readonly PlutoContext _context;

    public UnitOfWork(PlutoContext context)
    {
        _context = context;
        Courses = new CourseRepository(_context);
        Authors = new AuthorRepository(_context);
    }

    public ICourseRepository Courses { get; private set; }
    public IAuthorRepository Authors { get; private set; }

    public int Complete()
    {
        return _context.SaveChanges();
    }

    public void Dispose()
    {
        _context.Dispose();
    }
}