code: def valid_frameworks(self):
      return "tensorflow"
  
file_path: BigDL/python/nano/src/bigdl/nano/deps/neural_compressor/tensorflow/quantization.py
imports: from bigdl.nano.utils.common import invalidInputError
  from ..core import BaseQuantization
  from .metric import TensorflowINCMetric
  from .model import KerasQuantizedModel
  from .utils import Dataloader
  from bigdl.nano.utils.common import compare_version
  import operator
label_desc: Use image node_id 4 for calling the TensorflowQuantization obj's underlying member method code with example usage: obj.valid_frameworks() and returns: str