/// <summary>
/// Returns each subsection of <paramref name="fieldValue"/> which violates validation rules (e.g. the CHI found).
/// </summary>
/// <param name="fieldName"></param>
/// <param name="fieldValue"></param>
/// <returns></returns>
protected virtual IEnumerable <FailurePart> Validate(string fieldName, string fieldValue)
{
// make sure that we have a cache for this column name
var cache = Caches.GetOrAdd(fieldName, (v) => new MemoryCache(new MemoryCacheOptions()
{
SizeLimit = MaxValidationCacheSize
}));
//if we have the cached result use it
if (cache.TryGetValue(fieldValue ?? "NULL", out FailurePart[] result))
