code: def extract(data, items, out_dir=None):
      
      if vcfutils.get_paired_phenotype(data):
          if len(items) == 1:
              germline_vcf = _remove_prioritization(data["vrn_file"], data, out_dir)
              germline_vcf = vcfutils.bgzip_and_index(germline_vcf, data["config"])
              data["vrn_file_plus"] = {"germline": germline_vcf}
      return data
docs: Extract germline calls for the given sample, if tumor only.