code: def _trna_annotation(data):
      
      trna_ref = op.join(dd.get_srna_trna_file(data))
      name = dd.get_sample_name(data)
      work_dir = utils.safe_makedir(os.path.join(dd.get_work_dir(data), "trna", name))
      in_file = op.basename(data["clean_fastq"])
      tdrmapper = os.path.join(os.path.dirname(sys.executable), "TdrMappingScripts.pl")
      perl_export = utils.get_perl_exports()
      if not file_exists(trna_ref) or not file_exists(tdrmapper):
          logger.info("There is no tRNA annotation to run TdrMapper.")
          return work_dir
      out_file = op.join(work_dir, in_file + ".hq_cs.mapped")
      if not file_exists(out_file):
          with tx_tmpdir(data) as txdir:
              with utils.chdir(txdir):
                  utils.symlink_plus(data["clean_fastq"], op.join(txdir, in_file))
                  cmd = ("{perl_export} && perl {tdrmapper} {trna_ref} {in_file}").format(**locals())
                  do.run(cmd, "tRNA for %s" % name)
                  for filename in glob.glob("*mapped*"):
                      shutil.move(filename, work_dir)
      return work_dir
docs: use tDRmapper to quantify tRNAs