code: def _update_stats(self, branch, target_val, w):
      self.stats[branch].update(target_val, w)
  
file_path: river/river/tree/splitter/random_splitter.py
imports: from __future__ import annotations
  import abc
  import random
  import sys
  from river import stats
  from river.tree.splitter import Splitter
  from river.tree.utils import BranchFactory
label_desc: Use image node_id 2 for calling the RegRandomSplitter obj's underlying member method code with example usage: obj._update_stats(branch, target_val, w) without return types