docs: def inject_nmi(self):
          """Inject NMI, Non Maskable Interrupt.
  
          Inject NMI (Non Maskable Interrupt) for a node immediately.
  
          :raises: IloError, on an error from iLO
          """
          cur_status = self.get_host_power_status()
          if cur_status != 'ON':
              raise exception.IloError("Server is not in powered on state.")
  
          self._perform_power_op("Nmi")