public UnionIteratorN(SingleLinkedNode <IEnumerable <TSource> > sources, int headIndex, IEqualityComparer <TSource> comparer)
: base(comparer)
{
Debug.Assert(headIndex >= 2);
Debug.Assert(sources?.GetCount() == headIndex + 1);
_sources = sources;
_headIndex = headIndex;
}
public AppendPrependN(IEnumerable <TSource> source, SingleLinkedNode <TSource> prepended, SingleLinkedNode <TSource> appended, int prependCount, int appendCount)
: base(source)
{
Debug.Assert(prepended != null || appended != null);
Debug.Assert(prependCount > 0 || appendCount > 0);
Debug.Assert(prependCount + appendCount >= 2);
Debug.Assert((prepended?.GetCount() ?? 0) == prependCount);
Debug.Assert((appended?.GetCount() ?? 0) == appendCount);
_prepended = prepended;
_appended = appended;
_prependCount = prependCount;
_appendCount = appendCount;
}