public IQueryable<University> FilterUniversities(IQueryable<University> universities, FilterModel filter)
        {
            if (universities == null)
            {
                return universities;
            }

            universities = universities.OrderBy(u => u.Name);

            if (filter != null)
            {
                if (filter.Filter != null)
                {
                    universities = universities.Where(u => u.Name.Contains(filter.Filter));
                }

                if (filter.OrderBy != null)
                {
                    if (filter.Order == "asc")
                    {
                        if (filter.OrderBy == "name")
                        {
                            universities = universities.OrderBy(u => u.Name);
                        }
                        else if (filter.OrderBy == "country")
                        {
                            universities = universities.OrderBy(u => u.Country.Name);
                        }
                        else if (filter.OrderBy == "tuition")
                        {
                            universities = universities.OrderBy(u => u.TuitionFee);
                        }
                        else if (filter.OrderBy == "sat")
                        {
                            universities = universities.OrderBy(u => u.RequiredSAT);
                        }
                        else if (filter.OrderBy == "toeflpbt")
                        {
                            universities = universities.OrderBy(u => u.RequiredPBTToefl);
                        }
                        else if (filter.OrderBy == "toeflibt")
                        {
                            universities = universities.OrderBy(u => u.RequiredIBTToefl);
                        }
                    }
                    else
                    {
                        if (filter.OrderBy == "name")
                        {
                            universities = universities.OrderByDescending(u => u.Name);
                        }
                        else if (filter.OrderBy == "country")
                        {
                            universities = universities.OrderByDescending(u => u.Country);
                        }
                        else if (filter.OrderBy == "tuition")
                        {
                            universities = universities.OrderByDescending(u => u.TuitionFee);
                        }
                        else if (filter.OrderBy == "sat")
                        {
                            universities = universities.OrderByDescending(u => u.RequiredSAT);
                        }
                        else if (filter.OrderBy == "toeflpbt")
                        {
                            universities = universities.OrderByDescending(u => u.RequiredPBTToefl);
                        }
                        else if (filter.OrderBy == "toeflibt")
                        {
                            universities = universities.OrderByDescending(u => u.RequiredIBTToefl);
                        }
                    }
                }
            }

            return universities;
        }