private static void ExpandValueSet(ValueSet valueSet)
        {
            var settings = new ValueSetExpanderSettings
            {
                ValueSetSource = ValueSetResolvers.GetDirectorySource()
            };

            var expander = new CustomValueSetExpander(settings);

            expander.Expand(valueSet);
        }
        private static ValueSet GetValueSet(string key)
        {
            var valueSet = ValueSetResolvers.GetResolver().FindValueSet(key);

            valueSet.ShouldNotBeNull($"There was no ValueSet found at {key}.");

            ExpandValueSet(valueSet);

            Set(key, valueSet);

            return(valueSet);
        }