test: adds FindAccountsByCustomerID_CustomerNotFound test to BankATMTest

Author: tmcrockett252

lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BankAtmTest.java

@@ -85,6 +85,17 @@ void testDepositFunds_Check_AccountNotFound() {
         .withMessage("Account not found");
   }
 
+  @Test
+  void testFindAccountsByCustomerId_CustomerNotFound() {
+    UUID nonExistingCustomerId = UUID.randomUUID();
+
+    // Act
+    Set<Account> accounts = classUnderTest.findAccountsByCustomerId(nonExistingCustomerId);
+
+    // Assert
+    assertThat(accounts).isEmpty();
+  }
+
   @Test
   void testDepositFunds_Check() {
     // Arrange