code: def _build_lightgbm_operator_list():
      """
      List all supported LightGBM (Sklearn API) operators.
      """
      if lightgbm_installed():
          from lightgbm import (
              LGBMClassifier,
              LGBMRanker,
              LGBMRegressor,
              Booster,
          )
  
          return [LGBMClassifier, LGBMRanker, LGBMRegressor, Booster]
  
      return []
  
file_path: hummingbird/hummingbird/ml/supported.py
imports: from collections import defaultdict
  from .exceptions import MissingConverter
  from ._utils import torch_installed, sklearn_installed, lightgbm_installed, xgboost_installed, onnx_runtime_installed, tvm_installed, sparkml_installed, prophet_installed
label_desc: Use image node_id 4 for calling a global function with example usage: _build_lightgbm_operator_list() and returns: list, list