@Override
        public RequestBuilder parameters(List<String> pairs) {
            if (pairs.size() % 2 != 0)
                throw new IllegalArgumentException("Must supply parameter key/values in pairs");

            for (int i = 0; i < pairs.size(); ) {
                String key = pairs.get(i++), value = pairs.get(i++);
                if (value != null)
                    query = query.add(key, value);
            }

            return this;
        }
Builder for a request against a given set of hosts.
http-client/src/main/java/ai/vespa/hosted/client/AbstractHttpClient.java