docstr: Load existing model from model_path
  
  :param model_path: Path to the existing model.
  :return:
code: def load(self, model_path):
      """
      Load existing model from model_path
  
      :param model_path: Path to the existing model.
      :return:
      """
      raise NotImplementedError
  
file_path: analytics-zoo/pyzoo/zoo/orca/learn/base_estimator.py
imports: from abc import ABC, abstractmethod
label_desc: Use image node_id 6 for calling the BaseEstimator obj's underlying member method code with example usage: obj.load(model_path) without return types