The null writer discards its input. No point output is produced when using a null writer.
<?xml version="1.0" encoding="utf-8"?>
<Pipeline version="1.0">
<Writer type="writers.null">
<Filter type="filters.hexbin">
<Reader type="readers.las">
<Option name="filename">simple.las</Option>
</Reader>
</Filter>
</Writer>
</Pipeline>
When used with an option that forces metadata output, like --pipeline-serialization, this pipeline will create a hex boundary for the input file, but no output point data file will be produced.
The null writer discards all passed options.