code: def _refine_distances(self, xq_ds, idx, xb_ds, I):
      xq = xq_ds.get(idx).repeat(self.k, axis=0)
      xb = xb_ds.get(I.reshape(-1))
      if self.metric == faiss.METRIC_INNER_PRODUCT:
          return (xq * xb).sum(axis=1).reshape(I.shape)
      elif self.metric == faiss.METRIC_L2:
          return ((xq - xb) ** 2).sum(axis=1).reshape(I.shape)
      else:
          raise ValueError(f"metric not supported {self.metric}")
  
imports: import faiss
  import numpy
  import os
  from tqdm import tqdm, trange
  import sys
  import logging
  from faiss.contrib.ondisk import merge_ondisk
  from faiss.contrib.big_batch_search import big_batch_search
  from faiss.contrib.exhaustive_search import knn_ground_truth
  from faiss.contrib.evaluation import knn_intersection_measure
  from utils import get_intersection_cardinality_frequencies, margin, is_pretransform_index
  from dataset import create_dataset_from_oivf_config
label_desc: Use image node_id 12 for calling the OfflineIVF obj's underlying member method code with example usage: obj._refine_distances(xq_ds, idx, xb_ds, I) and returns: unknown, unknown