code: def valid_tuning_strategies(self):
      return "basic", "bayesian", "mse", "sigopt"
  
file_path: BigDL/python/nano/src/bigdl/nano/deps/neural_compressor/core/quantization.py
imports: from bigdl.nano.utils.common import invalidInputError
  from neural_compressor.conf.config import Quantization_Conf
  from neural_compressor.experimental import Quantization, common
label_desc: Use image node_id 9 for calling the BaseQuantization obj's underlying member method code with example usage: obj.valid_tuning_strategies() and returns: str,  str,  str,  str