public Mapper(DateTimeTransformer parent, DataViewSchema inputSchema) :
     base(parent.Host.Register(nameof(Mapper)), inputSchema, parent)
 {
     _parent     = parent;
     _cache      = new ConcurrentDictionary <long, TimePoint>();
     _oldestKeys = new ConcurrentQueue <long>();
 }
 public Mapper(DateTimeTransformer parent, DataViewSchema inputSchema) :
     base(parent.Host.Register(nameof(Mapper)), inputSchema, parent)
 {
     _parent = parent;
 }