code: def get_join_parameters(join_kwargs):
      
  
      by = join_kwargs.get('by', None)
      suffixes = join_kwargs.get('suffixes', ('_x', '_y'))
      if isinstance(by, tuple):
          left_on, right_on = by
      elif isinstance(by, list):
          by = [x if isinstance(x, tuple) else (x, x) for x in by]
          left_on, right_on = (list(x) for x in zip(*by))
      else:
          left_on, right_on = by, by
      return left_on, right_on, suffixes
docs: Convenience function to determine the columns to join the right and
      left DataFrames on, as well as any suffixes for the columns.