code: def get_test_data():
      df = pd.DataFrame()
      df["a"] = np.arange(100)
      df["b"] = 1 + (df["a"] % 2)
      return df
  
file_path: popmon/tests/popmon/alerting/test_apply_tl_bounds.py
imports: import numpy
  import pandas
  import pytest
  from popmon.alerting import ComputeTLBounds, DynamicBounds, StaticBounds, TrafficLightAlerts, pull_bounds, traffic_light
  from popmon.analysis.apply_func import ApplyFunc
  from popmon.analysis.functions import expanding_mean, expanding_std, pull, rolling_lr, rolling_mean
  from popmon.base import Pipeline
  from popmon.config import Settings
  from popmon.visualization.section_generator import SectionGenerator
label_desc: Use image node_id 1 for calling a global function with example usage: get_test_data() and returns: df