docs: def merge_two_dicts(x: Dict, y: Dict) -> Dict:
      """
      Given two dicts, merge them into a new dict as a shallow copy, e.g.
  
      .. code-block:: python
  
          z = merge_two_dicts(x, y)
  
      If you can guarantee Python 3.5, then a simpler syntax is:
  
      .. code-block:: python
  
          z = {**x, **y}
  
      See http://stackoverflow.com/questions/38987.
      """
      z = x.copy()
      z.update(y)
      return z