/// <summary>
/// Creates a new instance of a Planar Graph using a default NodeFactory
/// </summary>
public PlanarGraph()
{
_nodes = new NodeMap(new NodeFactory());
}
/// <summary>
/// Creates a new instance of a Planar Graph
/// </summary>
/// <param name="nodeFact">A node Factory</param>
public PlanarGraph(NodeFactory nodeFact)
{
_nodes = new NodeMap(nodeFact);
}