/// <summary>
/// This will return a new instance that combines the source instance's data with additional results - if results are being updated then the Remove method should
/// be called first to ensure that duplicate match data entries are not present in the returned index. This will never return null. It will throw an exception for
/// a null data reference or one that contains any null references.
/// </summary>
public IIndexData <TKey> Add(IEnumerable <KeyValuePair <string, NonNullImmutableList <WeightedEntry <TKey> > > > data)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
var newIndex = _data.Add(
data,
(current, toAdd) => ((current != null) && (toAdd != null)) ? current.AddRange(toAdd) : (current ?? toAdd)
);
return(new IndexData <TKey>(newIndex, KeyComparer, validate: false));
}
