func_code: _A = None
  
  
  def append2list(l1=_A, l2=_A):
      if l2 is _A:
          l2 = []
          for i in l1:
              l2.append(i)
          return l2
      elif l1 is _A:
          l1 = []
          for i in l2:
              l1.append(i)
          return l1