WindowsApiEmitter made easier to subclass.

queue_events now does not call read_events directly. The call
was put into a member function _read_events instead, to make
it easier to replace the read_events functionality while keeping
the rest of the class going.

src/watchdog/observers/read_directory_changes.py

@@ -71,8 +71,11 @@ def on_thread_stop(self):
         if self._handle:
             close_directory_handle(self._handle)
 
+    def _read_events(self):
+        return read_events(self._handle, self.watch.is_recursive)
+
     def queue_events(self, timeout):
-        winapi_events = read_events(self._handle, self.watch.is_recursive)
+        winapi_events = self._read_events()
         with self._lock:
             last_renamed_src_path = ""
             for winapi_event in winapi_events: