Stone.js API
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    eventBusBlueprint: EventBusBlueprint = ...

    Opt-in blueprint: import and register it (or use @EventBus()) to enable the emit side.

    It contributes the EventBusServiceProvider, which binds eventBus and eventBusManager. The listener side is the light key-router from @stone-js/router (@BusListener()). stone.providers is an array, so this merges.