### Question:
AwsRdsInstanceView { public Integer getBackupRetentionPeriod() { return databaseServer.getParameter(BACKUP_RETENTION_PERIOD, Integer.class); } AwsRdsInstanceView(DatabaseServer databaseServer); Long getAllocatedStorage(); Integer getBackupRetentionPeriod(); String getDBInstanceClass(); String getDBInstanceIdentifier(); String getEngine(); String getEngineVersion(); String getMasterUsername(); String getMasterUserPassword(); String getMultiAZ(); String getStorageType(); List<String> getVPCSecurityGroups();  }### Answer:
@Test public void testBackupRetentionPeriod() { when(server.getParameter(BACKUP_RETENTION_PERIOD, Integer.class)).thenReturn(Integer.valueOf("3")); assertEquals(3, underTest.getBackupRetentionPeriod().intValue()); }
@Test public void testNoBackupRetentionPeriod() { when(server.getParameter(BACKUP_RETENTION_PERIOD, Integer.class)).thenReturn(null); assertNull(underTest.getBackupRetentionPeriod()); }