public void AddDirectedEdge(int source, int destination, int weight = 0)
{
Vertice sourceVertice = GetVertice(source);
Vertice destinationVertice = GetVertice(destination);
if (sourceVertice == null || destinationVertice == null)
{
throw new ArgumentException("Given source value or destination value doesn't exist in graph.");
}
if (!sourceVertice.ContainsEdge(destinationVertice))
{
sourceVertice.AddEdge(destinationVertice, weight);
}
}