@Override
        public void close() throws IOException {
            synchronized (lock) {
                done = true;
                lock.notifyAll();
            }
            in.close();
        }
Same as {@link #feedMany(InputStream, ResultCallback)}, but without a provided {@link ResultCallback} instance.
@see JsonFeeder#feedMany(InputStream, ResultCallback) for details.
vespa-feed-client-api/src/main/java/ai/vespa/feed/client/JsonFeeder.java