code: def pandas_dummy_dataset(header):
      """Load sample dataset in pandas for testing; can be used to create a Spark dataframe
      Returns:
          single Pandas dataframe
      """
      ratings_dict = {
          header["col_user"]: [1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3],
          header["col_item"]: [1, 2, 3, 4, 1, 2, 7, 8, 9, 10, 1, 2],
          header["col_rating"]: [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
      }
      return pd.DataFrame(ratings_dict)
  
imports: import math
  from pathlib import Path
  import numpy
  import pandas
  from pyspark.sql import SparkSession
  import pytest
  from pandas.testing import assert_frame_equal
  from pysarplus import SARPlus, SARModel
label_desc: Use image node_id 4 for calling a global function with example usage: pandas_dummy_dataset(header) and returns: pd