code: def random_string(L=15, seed=None):
      return "".join(
          [seed.choice(string.ascii_letters) for n in range(L)]
      )
  
imports: import string
  from dataclasses import dataclass, field
  from enum import Enum
  from operator import itemgetter
  from queue import PriorityQueue
  import networkx
  from networkx.utils import py_random_state
  from .recognition import is_arborescence, is_branching
label_desc: Use image node_id 1 for calling a global function with example usage: random_string(L, seed) and returns: str