code: def repr_branch(self, index: int, shorten=False):
      feat_val = self._r_mapping[index]
  
      if shorten:
          return str(feat_val)
  
      return f"{self.feature} = {feat_val}"
  
imports: from __future__ import annotations
  import abc
  import math
  from ..base import Branch
label_desc: Use image node_id 6 for calling the NominalMultiwayBranch obj's underlying member method code with example usage: obj.repr_branch(index, shorten) and returns: self, str, feat_val, str