class_docstr: we test data loading, model instantiation, forecasting consistency, in particular
  (1) load a testing data
  (2) transform data
  (3) instantiate the model and train
  (4) forecast, and the forecasting result agrees with the reference
code: def __init__(self, *args, **kwargs):
      super().__init__(*args, **kwargs)
  
imports: import logging
  from os.path import abspath, dirname, join
  import sys
  import unittest
  from merlion.evaluate.forecast import ForecastMetric
  from merlion.models.forecast.trees import LGBMForecaster, LGBMForecasterConfig
  from merlion.models.utils.rolling_window_dataset import RollingWindowDataset
  from merlion.transform.sequence import TransformSequence
  from merlion.transform.resample import TemporalResample
  from merlion.transform.bound import LowerUpperClip
  from merlion.transform.normalize import MeanVarNormalize
  from merlion.utils import TimeSeries
  from ts_datasets.forecast import SeattleTrail
label_desc: Use image node_id 1 to create a new TestLGBMForecaster object from inherited base classes: unittest with example: obj = TestLGBMForecaster()