code: def _is_transformer(estimator):
      return hasattr(estimator, "fit_transform")
  
file_path: tpot/tpot/operator_utils.py
imports: import numpy
  from sklearn.base import BaseEstimator, is_classifier, is_regressor
  from sklearn.gaussian_process.kernels import Kernel
  import inspect
label_desc: Use image node_id 4 for calling a global function with example usage: _is_transformer(estimator) and returns: hasattr