code: def from_string(cls, txt):
      if (
          len(txt) == 4
          and txt[0] == txt[1]
          and txt[1] != txt[2]
          and txt[2] == txt[3]
          and txt[0] in CARDS
          and txt[2] in CARDS
      ):
          return cls(txt[0], txt[2])
  
imports: from functools import total_ordering
  from itertools import combinations
  from typing import Literal, Union
label_desc: Use image node_id 3 for calling the TwoPair obj's underlying member method code with example usage: obj.from_string(cls, txt) and returns: cls