private void copyStream(final Meta meta, final OutputStream outputStream) throws IOException {
        try (final Source streamSource = streamStore.openSource(meta.getId())) {
            SourceUtil.read(streamSource, outputStream);
        }
    }
Gets the next task to be processed.

@return The next task or null if there are currently no more tasks.
stroom-app/src/test/java/stroom/pipeline/task/TranslationTest.java