/// <summary>
 /// Private constructor. Makes a clone of a UserParameterSelection.
 /// </summary>
 /// <param name="userParameterSelection">UserParameterSelection to clone</param>
 private UserParameterSelection(UserParameterSelection userParameterSelection)
 {
     _factors = new FactorList(true);
     _factors.AddRange(userParameterSelection.Factors);
     _hosts = new TaxonList(true);
     _hosts.AddRange(userParameterSelection.Hosts);
     _individualCategories = new IndividualCategoryList(true);
     _individualCategories.AddRange(userParameterSelection.IndividualCategories);
     _periods = new PeriodList(true);
     _periods.AddRange(userParameterSelection.Periods);
     _references = new ReferenceList(true);
     _references.AddRange(userParameterSelection.References);
     _taxa = new TaxonList(true);
     _taxa.AddRange(userParameterSelection.Taxa);
 }