code: def run(items, background=None):
      
      paired = vcfutils.get_paired(items)
      if paired:
          inputs = [paired.tumor_data]
          background = [paired.normal_data] if paired.normal_bam else []
      else:
          assert not background
          inputs, background = sshared.find_case_control(items)
      work_dir = _sv_workdir(inputs[0])
      variant_file = _run_gridss(inputs, background, work_dir)
      out = []
      for data in items:
          sample_file = variant_file
          if "sv" not in data:
              data["sv"] = []
          effects_vcf, _ = effects.add_to_vcf(sample_file, data, "snpeff")
          data["sv"].append({"variantcaller": "gridss",
                             "vrn_file": effects_vcf or sample_file})
          out.append(data)
      return out
docs: Perform detection of structural variations with Manta.