From type/Telemetry/Sampler

See Original text in context

method set-instruments(Telemetry::Sampler:D @instruments --> Nil)

Allows one to change the instruments on an existing Instrument::Sampler object. Generally only used by calling it on the $*SAMPLER dynamic variable. Takes the same parameters as new, except that specifying no instruments will actually remove all of the instruments, effectively blocking any snap taking.