/// <inheritdoc cref="ImmutableHashSet{T}.Builder.UnionWith(IEnumerable{T})"/>
public void UnionWith(IEnumerable <T> other)
{
if (other is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.other);
}
if (_mutableSet is not null)
{
_mutableSet.UnionWith(other);
return;
}
if (other is ImmutableSegmentedHashSet <T> {
IsEmpty : true
})