The customData a CmcdReporter method accepts, for a reporter typed
C.
A reporter left on the default C constrains nothing, so requests carrying
any customData are accepted exactly as they were before C existed. A
reporter given a concrete C requires the request to satisfy it, because its
transforms read customData as C and would otherwise be handed a value
their type does not describe.
The
customDataa CmcdReporter method accepts, for a reporter typedC.A reporter left on the default
Cconstrains nothing, so requests carrying anycustomDataare accepted exactly as they were beforeCexisted. A reporter given a concreteCrequires the request to satisfy it, because its transforms readcustomDataasCand would otherwise be handed a value their type does not describe.