code: def add(self, thread):
      op = self.program[thread.pc]
      optype = type(op)
      if optype is Jmp:
          self.add(thread.at(op.x))
      elif optype is Split:
          self.add(thread.copy_at(op.x))
          self.add(thread.at(op.y))
      else:
          self.threads.append(thread)
  
imports: from whoosh.automata.fst import Arc
label_desc: Use image node_id 4 for calling the ThreadList obj's underlying member method code with example usage: obj.add(thread) without return types