code: def repr_branch(self, index: int, shorten=False):
      if shorten:
          if index == 0:
              return str(self.value)
          else:
              return f"not {self.value}"
      else:
          if index == 0:
              return f"{self.feature} = {self.value}"
          return f"{self.feature} ≠ {self.value}"
  
imports: from __future__ import annotations
  import abc
  import math
  from ..base import Branch
label_desc: Use image node_id 5 for calling the NominalBinaryBranch obj's underlying member method code with example usage: obj.repr_branch(index, shorten) and returns: self, str, self, str, str, self, self, str, self