@Test
public void testOnApplicationEventShouldSetInternalPort() {

    //GIVEN
    given(configurationAccess.getProperties()).willReturn(properties);
    given(properties.getProxyPort()).willReturn(internalPort);
    //WHEN
    underTest.onApplicationEvent(event);
    //THEN
    Integer actual = (Integer) Whitebox.getInternalState(underTest, "internalPort");
    assertEquals(actual, internalPort);
}