new changes

src/main/java/rocks/zipcode/quiz5/collections/Bank.java

@@ -10,7 +10,7 @@ import java.util.ArrayList;
  */
 public class Bank {
 
-    ArrayList<BankAccount> bank = new ArrayList<>();
+    private ArrayList<BankAccount> bank = new ArrayList<>();
 
     public BankAccount removeBankAccountByIndex(Integer indexNumber) {
 
@@ -19,12 +19,12 @@ public class Bank {
 
     public void addBankAccount(BankAccount bankAccount) {
 
-        bank.add(bankAccount);
+        this.bank.add(bankAccount);
 
     }
 
     public Boolean containsBankAccount(BankAccount bankAccount) {
 
-        return bank.contains(bankAccount);
+        return this.bank.contains(bankAccount);
     }
 }