docs: def set_host_power(self, power):
          """Toggle the power button of server.
  
          :param power: 'ON' or 'OFF'
          """
          if power.upper() in POWER_STATE:
              dic = {'HOST_POWER': POWER_STATE[power.upper()]}
              data = self._execute_command(
                  'SET_HOST_POWER', 'SERVER_INFO', 'write', dic)
              return data
          else:
              raise exception.IloInvalidInputError(
                  "Invalid input. The expected input is ON or OFF.")