code: def _add_dbsnp(orig_file, dbsnp_file, data, out_file=None, post_cl=None):
      
      orig_file = vcfutils.bgzip_and_index(orig_file, data["config"])
      if out_file is None:
          out_file = "%s-wdbsnp.vcf.gz" % utils.splitext_plus(orig_file)[0]
      if not utils.file_uptodate(out_file, orig_file):
          with file_transaction(data, out_file) as tx_out_file:
              conf_file = os.path.join(os.path.dirname(out_file), "dbsnp.conf")
              with open(conf_file, "w") as out_handle:
                  out_handle.write(_DBSNP_TEMPLATE % os.path.normpath(os.path.join(dd.get_work_dir(data), dbsnp_file)))
              if not post_cl: post_cl = ""
              cores = dd.get_num_cores(data)
              cmd = ("vcfanno -p {cores} {conf_file} {orig_file} | {post_cl} "
                     "bgzip -c > {tx_out_file}")
              do.run(cmd.format(**locals()), "Annotate with dbSNP")
      return vcfutils.bgzip_and_index(out_file, data["config"])
docs: Annotate a VCF file with dbSNP.
  
      vcfanno has flexible matching for NON_REF gVCF positions, matching
      at position and REF allele, matching ALT NON_REF as a wildcard.