adds BusinessCheckingAccount Tests

Author: TatsuyaRyujin

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

@@ -0,0 +1,22 @@
+package com.codedifferently.lesson17.bank;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+import org.junit.jupiter.api.Test;
+
+public class BusinessCheckingAccountTest {
+
+  @Test
+  void validateBusinessOwner_withBusinessOwner() {
+    Set<Customer> owners = new HashSet<>();
+    owners.add(new Customer(UUID.randomUUID(), "Elon Musk", CustomerType.BUSINESS));
+    owners.add(new Customer(UUID.randomUUID(), "Elon Musk", CustomerType.BUSINESS));
+
+    BusinessCheckingAccount account = new BusinessCheckingAccount("123456789", owners, 1000.0);
+    assertThat(account).isNotNull();
+  }
+}