Bank
-accounts map[int64]*account
-nextID int64
-mutex sync.RWMutex
+Initialize()
+OpenAccount(accountName string, accountPassword string, result *int64) : error
+CloseAccount(accountID int64, accountPassword string, result *bool) : error
+Withdraw(accountID int64, accountPassword string, quantity float64, result *bool) : error
+Deposit(accountID int64, accountPassword string, quantity float64, result *bool) : error
+PeekBalance(accountID int64, accountPassword string, result *float64) : error