code: def __init__(self, *args, **kwargs):
      super().__init__(*args, **kwargs)
      np.random.seed(1)
      self.data1 = np.arange(1000).tolist()
      self.data2 = np.random.uniform(-1e-8, 1e-8, 1000).tolist()
      self.data3 = np.random.uniform(-1e8, 1e8, 1000).tolist()
  
file_path: merlion/tests/forecast/test_istat.py
imports: import logging
  from merlion.utils.istat import Mean, Variance, ExponentialMovingAverage, RecencyWeightedVariance
  from os.path import abspath, dirname
  import sys
  import unittest
  import numpy
  import pandas
label_desc: Use image node_id 1 to create a new TestIStat object from inherited base classes: unittest with example: obj = TestIStat()