// LUCENENET specific: Pass iterator instead of the value, since this class knows the type to retrieve, but the caller does not.
public override void AddFromIterator(int doc, DocValuesFieldUpdatesIterator iterator)
{
Add(doc, ((Iterator)iterator).Value);
}
// LUCENENET specific - use this instance to decide which subclass to cast to, which will expose the
// strongly typed value. This allows us to access the long? type without boxing/unboxing.
// The Add() method was removed and replaced with the following two.
/// <summary>
/// Add an update to a document from a <see cref="DocValuesFieldUpdatesIterator"/>.
/// The <see cref="DocValuesFieldUpdatesIterator"/>'s value should be <c>null</c> to unset a value.
/// Note that the value is exposed by casting to the apprpriate <see cref="DocValuesFieldUpdatesIterator"/> subclasss.
/// </summary>
public abstract void AddFromIterator(int doc, DocValuesFieldUpdatesIterator iterator);