code: def similarity_search(x, y, dim, normalize=False):
      import faiss
  
      x = x.copy()
      y = y.copy()
      idx = faiss.IndexFlatL2(dim)
      if normalize:
          faiss.normalize_L2(x)
          faiss.normalize_L2(y)
      idx.add(x)
      scores, prediction = idx.search(y, 1)
      return prediction
  
imports: import numpy
  import torch
  from dataclasses import dataclass
  from typing import List
  from jiant.tasks.core import BaseExample, BaseTokenizedExample, BaseDataRow, BatchMixin, Task, TaskTypes
  from jiant.tasks.lib.templates.shared import construct_single_input_tokens_and_segment_ids, create_input_set_from_tokens_and_segments, labels_to_bimap
  from jiant.utils.python.io import read_file, read_file_lines
label_desc: Use image node_id 1 for calling a global function with example usage: similarity_search(x, y, dim, normalize) and returns: prediction