code: def _run_germline(bam_file, data, ref_file, region, out_file):
      
      work_dir = utils.safe_makedir("%s-work" % utils.splitext_plus(out_file)[0])
      region_bed = strelka2.get_region_bed(region, [data], out_file, want_gzip=False)
      example_dir = _make_examples(bam_file, data, ref_file, region_bed, out_file, work_dir)
      if _has_candidate_variants(example_dir):
          tfrecord_file = _call_variants(example_dir, region_bed, data, out_file)
          return _postprocess_variants(tfrecord_file, data, ref_file, out_file)
      else:
          return vcfutils.write_empty_vcf(out_file, data["config"], [dd.get_sample_name(data)])
docs: Single sample germline variant calling.