private void verifyHeadersForGetBlobNotModified(MockRestResponseChannel restResponseChannel, Container container) {
    Assert.assertNotNull("Date has not been set", restResponseChannel.getHeader(RestUtils.Headers.DATE));
    Assert.assertNotNull("Last-Modified has not been set",
        restResponseChannel.getHeader(RestUtils.Headers.LAST_MODIFIED));
    Assert.assertNull("Content length should not be set",
        restResponseChannel.getHeader(RestUtils.Headers.CONTENT_LENGTH));
    Assert.assertNull("Accept-Ranges should not be set",
        restResponseChannel.getHeader(RestUtils.Headers.ACCEPT_RANGES));
    Assert.assertNull("Content-Range header should not be set",
        restResponseChannel.getHeader(RestUtils.Headers.CONTENT_RANGE));
    verifyCacheHeaders(container, restResponseChannel);
    verifyAbsenceOfHeaders(restResponseChannel, RestUtils.Headers.BLOB_SIZE, RestUtils.Headers.CONTENT_TYPE,
        RestUtils.Headers.LIFE_VERSION);
  }
Verify the headers from the response for a Not modified blob are as expected
@param restResponseChannel {@link MockRestResponseChannel} from which headers are to be verified
@param container the {@link Container}.
ambry-frontend/src/test/java/com/github/ambry/frontend/AmbrySecurityServiceTest.java