code: def _survivor_merge(call_vcf, truth_vcf, stats, work_dir, data):
      
      out_file = os.path.join(work_dir, "eval-merge.vcf")
      if not utils.file_uptodate(out_file, call_vcf):
          in_call_vcf = call_vcf.replace(".vcf.gz", ".vcf")
          if not utils.file_exists(in_call_vcf):
              with file_transaction(data, in_call_vcf) as tx_in_call_vcf:
                  do.run("gunzip -c {call_vcf} > {tx_in_call_vcf}".format(**locals()))
          in_truth_vcf = truth_vcf.replace(".vcf.gz", ".vcf")
          if not utils.file_exists(in_truth_vcf):
              with file_transaction(data, in_truth_vcf) as tx_in_truth_vcf:
                  do.run("gunzip -c {truth_vcf} > {tx_in_truth_vcf}".format(**locals()))
          in_list_file = os.path.join(work_dir, "eval-inputs.txt")
          with open(in_list_file, "w") as out_handle:
              out_handle.write("%s\n%s\n" % (in_call_vcf, in_truth_vcf))
          with file_transaction(data, out_file) as tx_out_file:
              cmd = ("SURVIVOR merge {in_list_file} {stats[merge_size]} 1 0 0 0 {stats[min_size]} {tx_out_file}")
              do.run(cmd.format(**locals()), "Merge SV files for validation: %s" % dd.get_sample_name(data))
      return out_file
docs: Perform a merge of two callsets using SURVIVOR,