public void GetAverageTextLengthByGender_ShouldReturnZero_WhenNoEntitiesToAverage()
        {
            var configuration = new MapperConfiguration(cfg => { cfg.AddProfile <PerPeriodProfile>(); });
            var mapper        = new Mapper(configuration);
            var mapperHelper  = new EntityMapper(mapper);

            var entities = new List <MessageByGenderEntity>();

            var total = mapperHelper.GetAverageTextLengthByGender(entities, "M");

            Assert.Equal(0, total);
        }