code: def change_dict_keys(self, data_dict, prefix):
          
  
          keys = data_dict.keys()
          dummy_dict = copy.deepcopy(data_dict)
          changed_dict = {}
          for key in keys:
              changed_dict[prefix + str(key)] = dummy_dict.pop(key)
          return changed_dict
docs: Prefixes 'L_'/'R_' to the collection keys
              :param data_dict: dictionary which is to be altered
              :type  data_dict: dict
  
              :param prefix: prefix to be attached before every key
              :type  prefix: string
  
              :return dict_: dict