Installs the phase observer, or clears it when passed null.
Called by initialize from config.onPhase; exported so tests and
benchmark harnesses can attach a collector without reinitializing. It applies
to the default instance only: a client takes its observer from its own
onPhase.
Installs the phase observer, or clears it when passed
null.Called by initialize from
config.onPhase; exported so tests and benchmark harnesses can attach a collector without reinitializing. It applies to the default instance only: a client takes its observer from its ownonPhase.