private void addToHeader(HttpHeaders headers, CharSequence key, CharSequence value) {
        if (StringUtils.isNotEmpty(value)) {
            headers.add(key, value);
        }
    }
@author <a href="mailto:zhanggeng.zg@antfin.com">GengZhang</a>
test/test-integration/src/test/java/com/alipay/sofa/rpc/transport/http/Http2ClearTextBadRequestTest.java