protected static IList<TimePeriod> RemoveEarlyEmptyTimePeriods(PartitionTrendDataDictionaryBuilder dictionaryBuilder,
     IList<TimePeriod> timePeriods)
 {
     int earliestIndexRemoved = dictionaryBuilder.RemoveEarlyEmptyYears();
     return earliestIndexRemoved > -1
         ? timePeriods.Skip(earliestIndexRemoved + 1).ToList()
         : timePeriods;
 }
        public void When_Non_Valid_Early_Data_Then_Remove_Index_Is_First_With_Data()
        {
            var entities = new List<INamedEntity>
            {
                new Sex {Id = Sex1},
                new Sex {Id = Sex2},
            };

            var builder = new PartitionTrendDataDictionaryBuilder(entities, PartitionDataType.Sex);

            AddNullData(builder);
            AddNullData(builder);
            AddValidData(builder);

            var index = builder.RemoveEarlyEmptyYears();

            // Assert
            Assert.AreEqual(1, index);
            Assert.AreEqual(1, builder.Dictionary[Sex2].Count, "Expect 1 data point because two were removed");
        }