@Test
public void extractIntegerHeader_shouldReturnIntegerValue() throws Exception {

    response.addHeader(AD_TIMEOUT.getKey(), "10");
    assertThat(HeaderUtils.extractIntegerHeader(response, AD_TIMEOUT)).isEqualTo(10);
    response.addHeader(AD_TIMEOUT.getKey(), "0");
    assertThat(HeaderUtils.extractIntegerHeader(response, AD_TIMEOUT)).isEqualTo(0);
    response.addHeader(AD_TIMEOUT.getKey(), "-2");
    assertThat(HeaderUtils.extractIntegerHeader(response, AD_TIMEOUT)).isEqualTo(-2);
}