GetLoggableValue returns the value of the metadata currently attached to the Context.

LogIfError makes it less verbose to defer a Close() call while handling an unlikely-but-possible error return by logging it.

WatchingLoggable attaches a Loggable to the Context.

WithField attaches a key-value pair to a Context.

WithFields attaches fields to a Context.

WithLoggable attaches a Loggable's fields to the Context.

Valuer is essentially a Context, but down-scoped to what Loggable expects.