code: def _compatible_small_variants(data, items):
      
      from bcbio import heterogeneity
      VarFile = collections.namedtuple("VarFile", ["name", "sample", "normal"])
      out = []
      paired = vcfutils.get_paired(items)
      for v in heterogeneity.get_variants(data, include_germline=not paired):
          vrn_file = v["vrn_file"]
          base, ext = utils.splitext_plus(os.path.basename(vrn_file))
          if paired:
              out.append(VarFile(vrn_file, paired.tumor_name, paired.normal_name))
          else:
              out.append(VarFile(vrn_file, dd.get_sample_name(data), None))
      return out
docs: Retrieve small variant (SNP, indel) VCFs compatible with CNVkit.