code: def create_panel_of_normals(items, group_id, work_dir):
      
      out_file = os.path.join(work_dir, "%s-%s-pon.hdf5" % (dd.get_sample_name(items[0]), group_id))
      if not utils.file_exists(out_file):
          with file_transaction(items[0], out_file) as tx_out_file:
              params = ["-T", "CreateReadCountPanelOfNormals",
                        "-O", tx_out_file,
                        "--annotated-intervals", tz.get_in(["regions", "bins", "gcannotated"], items[0])]
              for data in items:
                  params += ["-I", tz.get_in(["depth", "bins", "target"], data)]
              _run_with_memory_scaling(params, tx_out_file, items[0], ld_preload=True)
      return out_file
docs: Create a panel of normals from one or more background read counts.