code: def load(cls, serialized_index):
          
          from lunr import __TARGET_JS_VERSION__
  
          if isinstance(serialized_index, basestring):
              serialized_index = json.loads(serialized_index)
  
          if serialized_index["version"] != __TARGET_JS_VERSION__:
              logger.warning(
                  "Version mismatch when loading serialized index. "
                  "Current version of lunr {} does not match that of serialized "
                  "index {}".format(__TARGET_JS_VERSION__, serialized_index["version"])
              )
  
          field_vectors = {
              ref: Vector(elements) for ref, elements in serialized_index["fieldVectors"]
          }
  
          tokenset_builder = TokenSetBuilder()
          inverted_index = {}
          for term, posting in serialized_index["invertedIndex"]:
              tokenset_builder.insert(term)
              inverted_index[term] = posting
  
          tokenset_builder.finish()
  
          return Index(
              fields=serialized_index["fields"],
              field_vectors=field_vectors,
              inverted_index=inverted_index,
              token_set=tokenset_builder.root,
              pipeline=Pipeline.load(serialized_index["pipeline"]),
          )
docs: Load a serialized index