class_docstr: Helper class used to assemble branches designed by the splitters.
  
  If constructed using the default values, a null-split suggestion is assumed.
code: def assemble(
      self,
      branch,  # typing.Type[DTBranch],
      stats: dict | Var,
      depth: int,
      *children,
      **kwargs,
  ):
      return branch(
          stats,
          self.feature,
          self.split_info,
          depth,
          *children,
          **kwargs,
      )
  
imports: from __future__ import annotations
  import collections
  import copy
  import dataclasses
  import functools
  import math
  import sys
  import typing
  from river.base.typing import FeatureName
  from river.stats import Cov, Var
label_desc: Use image node_id 1 for calling the BranchFactory obj's underlying member method code with example usage: obj.assemble(branch, stats, depth) and returns: branch