code: def start(self):
      self._start = time.time()
  
imports: import time
  import numpy
  import torch
  import typing
  from sklearn import preprocessing
  from sklearn.metrics.pairwise import cosine_similarity
  import tqdm
  import tabulate
  import autogl.data.graph
  from ._feature_engineer import FeatureEngineer
  from .._data_preprocessor_registry import DataPreprocessorUniversalRegistry
  from ._selectors import GBDTFeatureSelector
  from ....utils import get_logger
label_desc: Use image node_id 2 for calling the Timer obj's underlying member method code with example usage: obj.start() without return types