Added `_bus` property on `Plugin`.

platypush/plugins/__init__.py

@@ -101,6 +101,15 @@ class Plugin(EventGenerator, ExtensionWithManifest):  # lgtm [py/missing-call-to
         assert redis, 'db plugin not initialized'
         return redis
 
+    @property
+    def _bus(self):
+        """
+        :return: The reference to the :class:`platypush.bus.Bus`.
+        """
+        from platypush.context import get_bus
+
+        return get_bus()
+
     @property
     def _entities(self):
         """