docstr: Evaluate model.
  
  :param data: evaluation data.
  :param batch_size: batch size per thread.
  :return: evaluation result as a dictionary of {'metric name': metric value}
docstr_tok: ["Evaluate","model",".",":","param","data",":","evaluation","data",".",":","param","batch_size",":","batch","size","per","thread",".",":","return",":","evaluation","result","as","a","dictionary","of","{","'metric","name","'",":","metric","value","}"]
code: def evaluate(self, data, batch_size):
      """
      Evaluate model.
  
      :param data: evaluation data.
      :param batch_size: batch size per thread.
      :return: evaluation result as a dictionary of {'metric name': metric value}
      """
      invalidInputError(False, "not implemented")
  
file_path: BigDL/python/orca/src/bigdl/orca/learn/base_estimator.py
imports: from abc import ABC, abstractmethod
  from bigdl.dllib.utils.log4Error import invalidInputError
label_desc: Use image node_id 3 for calling the BaseEstimator obj's underlying member method code with example usage: obj.evaluate(data, batch_size) without return types