code: def test_init(header):
      model = SAR(similarity_type="jaccard", **header)
  
      assert model.col_user == "UserId"
      assert model.col_item == "MovieId"
      assert model.col_rating == "Rating"
      assert model.col_timestamp == "Timestamp"
      assert model.col_prediction == "prediction"
      assert model.similarity_type == "jaccard"
      assert model.time_decay_half_life == 2592000
      assert not model.time_decay_flag
      assert model.time_now is None
      assert model.threshold == 1
  
imports: import json
  import pytest
  import itertools
  import numpy
  import pandas
  from pandas.testing import assert_frame_equal
  from recommenders.utils.constants import DEFAULT_PREDICTION_COL
  from recommenders.models.sar import SAR
label_desc: Use image node_id 1 for calling a global function with example usage: test_init(header) without return types