code: def get_select_items(items):
      
      option_items = list()
      for item in items:
          if isinstance(item, dict) and defs.VALUE in item and defs.LABEL in item:
              option_items.append(item[defs.VALUE])
          else:
              raise exceptions.ParametersFieldError(item, "a dictionary with {} and {}"
                                                    .format(defs.LABEL, defs.VALUE))
      return option_items
docs: Return list of possible select items.