     func execute(board: GameBoard) throws {
         //nop
     }
-    
+
 }
 
 

//

import Foundation
private struct NoWeight : Comparable, Summable {
    private init() {}
    static let value:NoWeight = NoWeight()
}

private func +(lhs: NoWeight, rhs: NoWeight) -> NoWeight {
    return lhs
}
private func <(lhs:NoWeight, rhs:NoWeight) -> Bool {
    return false
}

private func ==(lhs:NoWeight, rhs:NoWeight) -> Bool {
    return true
}

public class GameBoard {


    private var positions:[Pandemic.Character:Int]

    private let graph:WeightedGraph<City,NoWeight>


    init(withCharacters characters:[Pandemic.Character], inCity city:City) {

    }


    private static func createPandemicMap() -> WeightedGraph<City,OpenOrBlocked> {

        let graph = WeightedGraph<City,OpenOrBlocked>()

        let algiersIndex = graph.addVertex(City.algiers)
        let atlantaIndex = graph.addVertex(City.atlanta)
