
  -spec erlang:system_monitor() -> MonSettings
                                 when
                                     MonSettings ::
                                         undefined | {MonitorPid, Options},
                                     MonitorPid :: pid(),
                                     Options :: [system_monitor_option()].

  Types:
    -type system_monitor_option() ::
          busy_port | busy_dist_port |
          {long_gc, non_neg_integer()} |
          {long_schedule, non_neg_integer()} |
          {large_heap, non_neg_integer()}.

  Returns the current system monitoring settings set by 
  erlang:system_monitor/2 as {MonitorPid, Options}, or undefined
  if no settings exist. The order of the options can be different
  from the one that was set.
