code: def _return_wrapper(fits, return_all, start, trace):
      
      # make sure it's an iterable
      if not is_iterable(fits):
          fits = [fits]
  
      # whether to print the final runtime
      if trace:
          print('Total fit time: %.3f seconds' % (time.time() - start))
  
      # which to return? if not all, then first index (assume sorted)
      if not return_all:
          return fits[0]
      return fits
docs: If the user wants to get all of the models back, this will
      return a list of the ARIMA models, otherwise it will just return
      the model. If this is called from the end of the function, ``fits``
      will already be a list.
  
      We *know* that if a function call makes it here, ``fits`` is NOT None
      or it would have thrown an exception in :func:`_post_ppc_arima`.
  
      Parameters
      ----------
      fits : iterable or ARIMA
          The ARIMA(s)
  
      return_all : bool
          Whether to return all.