          here.with(immediate: no).stage new Native ->
          
          listener = sinon.spy()
-         here.on 'flushed', listener
+         here.once 'flushed', listener
          
          expect(here.realize()).to.be.ok()
          expect(listener).was.notCalled()

         here.with(immediate: no).stage requestor, undefined, new Mask mutex
         
         listener = sinon.spy()
         here.on 'flushed', listener
         
         expect(here.realize()).to.be.ok()
         expect(listener).was.calledWith 1

         here.with(immediate: no).stage new Native ->
         
         listener = sinon.spy()
         here.once 'flushed', listener
         
         expect(here.realize()).to.be.ok()
      
