public LibKeyMap <TItem> OverrideWith(LibKeyMap <TItem> overrides)
{
var newKeys = _index.MergeKeys(overrides._index);
var newItems = ImmutableList.ValueOf(newKeys.Select(key =>
{
TItem item;
if (!overrides.TryGetValue(key, out item))
{
bool b = TryGetValue(key, out item);
Assume.IsTrue(b);
}
return(item);
}));
return(new LibKeyMap <TItem>(newItems, newKeys));
}
public override bool TryGetValue(LibKey key, out TItem value)
{
return(_libKeyMap.TryGetValue(key, out value));
}