code: def _check_base_estimator(estimator):
      """Validates base estimator"""
      return hasattr(estimator, "fit") and hasattr(estimator, "predict")
  
imports: import numbers
  import numpy
  from itertools import compress
  from scipy.sparse import issparse
  from sklearn.model_selection import ParameterGrid
  from sklearn.utils.validation import check_is_fitted
label_desc: Use image node_id 5 for calling a global function with example usage: _check_base_estimator(estimator) and returns: unknown