public Bucket Except <TValue2>(HashedAvlTree <TKey, TValue2> .Bucket other, Lineage lineage,
ValueSelector <TKey, TValue, TValue2, Optional <TValue> > subtraction = null)
{
var newBucket = Empty;
foreach (var item in Items)
{
var findOther = other.Find(item.Key);
if (findOther.IsNone)
{
newBucket = NewBucket(item.Key, item.Value, newBucket, lineage);
}
else if (subtraction != null)
{
var newValue = subtraction(item.Key, item.Value, findOther.Value);
if (newValue.IsSome)
{
newBucket = NewBucket(item.Key, newValue.Value, newBucket, lineage);
}
}
}
return(newBucket);
}