code: def _identity(X):
      """The identity function."""
      return X
  
file_path: catboost/contrib/python/scikit-learn/py2/sklearn/preprocessing/_function_transformer.py
imports: from ..base import BaseEstimator, TransformerMixin
  from ..utils import check_array
label_desc: Use image node_id 1 for calling a global function with example usage: _identity(X) and returns: X