class_docstr: Mock classifier object for testing.
code: def predict(self, *args, **kwargs):
      if not self.fitted:
          raise NotFittedError
  
      return self.predict_return
  
imports: from sklearn.exceptions import NotFittedError
label_desc: Use image node_id 3 for calling the MockEstimator obj's underlying member method code with example usage: obj.predict() and returns: self