code: def _drift_input(self, y, y_hat) -> int | float:
      pass
  
imports: from __future__ import annotations
  import abc
  import collections
  import math
  import random
  import sys
  from river import base, drift, metrics, tree, utils
  from river.tree.nodes.et_nodes import ETLeafAdaptive, ETLeafMean, ETLeafModel
  from river.tree.splitter.random_splitter import RegRandomSplitter
label_desc: Use image node_id 3 for calling the ExtraTrees obj's underlying member method code with example usage: obj._drift_input(y, y_hat) without return types