1. @DomName('PushSubscription.getKey')
  2. @DocsEditable()
  3. @Experimental()
ByteBuffer getKey(String name)

Source 

@DomName('PushSubscription.getKey')
@DocsEditable()
@Experimental() // untriaged
ByteBuffer getKey(String name) =>
    _blink.BlinkPushSubscription.instance.getKey_Callback_1_(this, name);