anchor.diff:  	"GOOGLE_MASTER_BILLING_ACCOUNT",
   }
   
  +var mutex = &sync.Mutex{}
  +
   func init() {
   	configs = make(map[string]*Config)
   	sources = make(map[string]VcrSource)
  
positive.code: 		seed := rand.Int63()
  		s := rand.NewSource(seed)
  		vcrSource := VcrSource{seed: seed, source: s}
  		sources[t.Name()] = vcrSource
  		return &vcrSource, nil
  	case "REPLAYING":
  		seed, err := readSeedFromFile(vcrSeedFile(path, t.Name()))
  
negative.code: 			}
  		}
  		// Clean up test config
  		mutex.Lock()
  		delete(configs, t.Name())
  		delete(sources, t.Name())
  		mutex.Unlock()
  	}
  }
  
  