@Test
public void testFormatTemplateWithoutExistingHeader() {

    //GIVEN
    //SetUp
    given(request.getHeader(SuppressGzipCompression.HEADER_KEY_ACCEPT_ENCODING)).willReturn(SuppressGzipCompression.HEADER_VALUE_GZIP);
    given(response.getHeader(SuppressGzipCompression.HEADER_KEY_SUPPRESS_ENCODING)).willReturn(null);
    //WHEN
    underTest.formatResponse(request, response, null, parameterMap);
    //THEN
    verify(response).addHeader(SuppressGzipCompression.HEADER_KEY_SUPPRESS_ENCODING, SuppressGzipCompression.HEADER_VALUE_GZIP);
}