code: def split_namedpipe_cls(pair1_file, pair2_file, data):
      
      if "align_split" in data:
          start, end = [int(x) for x in data["align_split"].split("-")]
      else:
          start, end = None, None
      if pair1_file.endswith(".sdf"):
          assert not pair2_file, pair2_file
          return rtg.to_fastq_apipe_cl(pair1_file, start, end)
      else:
          out = []
          for in_file in pair1_file, pair2_file:
              if in_file:
                  assert _get_grabix_index(in_file), "Need grabix index for %s" % in_file
                  out.append("<(grabix grab {in_file} {start} {end})".format(**locals()))
              else:
                  out.append(None)
          return out
docs: Create a commandline suitable for use as a named pipe with reads in a given region.