@Test
public void virtualMachineIDsEmptyTest() throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException {

    when(vsg.getId()).thenReturn(1L);
    SecurityGroupResponse securityGroupResponse = _securityGroupJoinDaoImpl.newSecurityGroupResponse(vsg, caller);
    Field fieldVirtualMachineIds = securityGroupResponse.getClass().getDeclaredField("virtualMachineIds");
    fieldVirtualMachineIds.setAccessible(true);
    Set<String> virtualMachineIds = (Set<String>)fieldVirtualMachineIds.get(securityGroupResponse);
    assertEquals(0, virtualMachineIds.size());
}