code: def reverse_dict(dict_obj):
      
      new_dict = {}
      for key in dict_obj:
          add_to_dict_val_set(dict_obj=new_dict, key=dict_obj[key], val=key)
      for key in new_dict:
          new_dict[key] = sorted(new_dict[key], reverse=False)
      return new_dict
docs: Reverse a dict, so each value in it maps to a sorted list of its keys.
  
      Parameters
      ----------
      dict_obj : dict
          A key-value dict.
  
      Returns
      -------
      dict
          A dict where each value maps to a sorted list of all the unique keys
          that mapped to it.
  
      Example
      -------
      >>> dicti = {'a': 1, 'b': 3, 'c': 1}
      >>> reverse_dict(dicti)
      {1: ['a', 'c'], 3: ['b']}