public static Dictionary <string, (IEnumerable <Teacher> domains, IEnumerable <string> relations)> CreateTestData()
        {
            var teachers = CreateTeachers().ToList();

            var variablesId = CreateVariablesId().ToList();

            var relations = new Dictionary <string, List <string> >();

            // Create simultaneously hours relations
            for (var h = 1; h <= NumOfDayHours; h++)
            {
                var hour      = h.ToString();
                var neighbors = variablesId.Where(v => DomainUtils.DecodeHour(v).Equals(hour)).ToList();

                foreach (var nv in neighbors)
                {
                    relations.Add(nv, neighbors.Where(n =>
                                                      n != nv &&                                                  // Exclude itself
                                                      DomainUtils.DecodeDay(nv).Equals(DomainUtils.DecodeDay(n))) // Same day
                                  .ToList());
                }
            }

            // Create previous/next hours relations
            for (var d = 1; d <= NumOfWeekDays; d++)
            {
                var day       = d.ToString();
                var neighbors = variablesId.Where(v => DomainUtils.DecodeDay(v).Equals(day)).ToList();

                foreach (var @class in Classes)
                {
                    var neighborsOfCurrClass = neighbors.Where(v => DomainUtils.DecodeClass(v).Equals(@class)).ToList();

                    foreach (var nv in neighborsOfCurrClass)
                    {
                        var currentHour = int.Parse(DomainUtils.DecodeHour(nv));
                        relations.First(v => v.Key == nv).Value.AddRange(neighborsOfCurrClass.Where(n =>
                        {
                            var h = int.Parse(DomainUtils.DecodeHour(n));
                            return(h + 1 == currentHour || h - 1 == currentHour);
                        }));
                    }
                }
            }

            var data = new Dictionary <string, (IEnumerable <Teacher> domains, IEnumerable <string> relations)>(
                variablesId.Select(v => new KeyValuePair <string, (IEnumerable <Teacher> domains, IEnumerable <string> relations)>(
                                       v, (teachers, relations.Where(r => r.Key == v).SelectMany(r => r.Value))
                                       ))
                );

            return(data);
        }