### Question:
HeartbeatDatabaseInfo extends HeartbeatInfo { public String getKey() { return getDatabaseName() + "|" + getDatabaseName(); }  String getDatabaseName(); void setDatabaseName(String databaseName); String getDatabaseVersion(); void setDatabaseVersion(String databaseVersion); void contributeToHttpCall(HeartbeatCall call); String getKey();  }### Answer:
@Test void getKey_instanceWithDefaultValues_null() { assertEquals(KEY_FOR_NULL, objectUnderTest.getKey()); }