code: def is_fitted(self):
      return (
          hasattr(self.model, "n_features_in_")
          and self.model.n_features_in_ is not None
          and self.model.n_features_in_ > 0
      )
  
imports: import copy
  import logging
  import time
  import warnings
  import joblib
  import numpy
  import pandas
  from supervised.algorithms.algorithm import BaseAlgorithm
  from supervised.algorithms.registry import BINARY_CLASSIFICATION, MULTICLASS_CLASSIFICATION, REGRESSION
  from supervised.utils.config import LOG_LEVEL
  from supervised.utils.metric import Metric
label_desc: Use image node_id 6 for calling the SklearnAlgorithm obj's underlying member method code with example usage: obj.is_fitted() and returns: unknown