// Adds a new object to a given sequence of transition keys in the
// graph. Traverses existing transitions and adds new states and
// transitions as necessary.
public void Add(IEnumerable <TransitionKey> rgtkTerminal, Terminal obj)
{
StateNode state = _stateRoot;
foreach (TransitionKey tk in rgtkTerminal)
{
state = state.NextState(tk, true);
}
state.AddTerminalObj(obj);
}