internal ForestInternal(InteriorNode node, Nonterminal nonterminal) : base(node.StartPosition, node.EndPosition)
{
_node = node;
_nonterminal = nonterminal;
//_nodeLookup = new Dictionary<InteriorNode, ForestInternal>();
//_nodeLookup[node] = this;
_options = ForestOption.BuildOptions(node.Families, node.StartPosition, node.EndPosition);
}