public List<String> getOutputs() {
        return Collections.unmodifiableList(outputs);
    }
A filter used to sample the output produced by SAX events at any point in the
XML pipeline. Many instances of this filter can be used.
<p>
This filter accumulates all the complete documents so they can be asserted against at the end of parsing.
stroom-pipeline/src/main/java/stroom/pipeline/filter/TestFilter.java