code: def run(align_bams, items, ref_file, assoc_files, region, out_file):
      
      call_file = "%s-raw.vcf.gz" % utils.splitext_plus(out_file)[0]
      strelka_work_dir = "%s-work" % utils.splitext_plus(out_file)[0]
      paired = vcfutils.get_paired_bams(align_bams, items)
      if paired:
          assert paired.normal_bam, "Strelka2 requires a normal sample"
          call_file = _run_somatic(paired, ref_file, assoc_files, region, call_file, strelka_work_dir)
      else:
          call_file = _run_germline(align_bams, items, ref_file,
                                    assoc_files, region, call_file, strelka_work_dir)
      return _af_annotate_and_filter(paired, items, call_file, out_file)
docs: Run strelka2 variant calling, either paired tumor/normal or germline calling.
  
      region can be a single region or list of multiple regions for multicore calling.