NewDistributor returns a new `Distributor`.

NewEventCertificate returns a new `EventCertificate`.

NewEventMeasurement returns a new `EventMeasurement`.

NewEventMonitor returns a new `EventMonitor`.

NewHTTPProbe returns a new `HTTPProbe`.

NewICMPProbe returns a new `ICMPProbe`.

NewMonitorService returns a new `MonitorService`.

NewPluginProbe returns a new `PluginProbe`.

NewTCPProbe returns a new `TCPProbe`.

Distributor handles polling actions, and distributes `Measurement` information.

Event is a plugin that can be executed based on a measurement state.

EventCertificate is a `Certificate` safe for use in plugin argument templates.

EventMeasurement is a `Measurement` safe for use in plugin argument templates.

EventMonitor is a `Monitor` safe for use in plugin argument templates.

MeasurementMessage is used to distribute a `Measurement` to the repository and feed subscribers.

Monitor is the monitor domain type.

MonitorService is a service used to interact with the monitor domain type.

PluginExecutor can execute a plugin identified by a `PluginFields`.

PollMessage is used to manually trigger a poll action.

SelectMeasurementParams is a set of parameters used to narrow the scope of the `SelectMeasurement` repository method.

SelectMonitorParams is a set of parameters used to narrow the scope of the `SelectMonitor` repository method.

StartMessage is used to begin polling a `Monitor`.

StopMessage is used to stop polling an active `Monitor`.

SubscribeMessage is used to add a new feed subscriber.

UnsubscribeMessage is used to remove an existing feed subscriber, and close the connection.

MonitorRepository is a type used to interact with the monitor domain database table.

Probe is a type used to build a `Span` describing the state of a resource.