code: def extend(*args):
      
      if not args:
          return {}
  
      first = args[0]
      rest = args[1:]
      out = type(first)(first)
      for each in rest:
          out.update(each)
      return out
docs: shallow dictionary merge
  
      Args:
          a: dict to extend
          b: dict to apply to a
  
      Returns:
          new instance of the same type as _a_, with _a_ and _b_ merged.