Add doc-string warnings for destroy() methods (#1204)

* publisher.py: add doc-string warning for destroy method

Signed-off-by: Steve Peters <[email protected]>

* subscription.py: add doc-string warning for destroy method

Signed-off-by: Steve Peters <[email protected]>

---------

Signed-off-by: Steve Peters <[email protected]>

Author: scpeters

rclpy/rclpy/publisher.py

@@ -88,6 +88,12 @@ def handle(self):
         return self.__publisher
 
     def destroy(self):
+        """
+        Destroy a container for a ROS publisher.
+
+        .. warning:: Users should not destroy a publisher with this method, instead they should
+           call :meth:`.Node.destroy_publisher`.
+        """
         for handler in self.event_handlers:
             handler.destroy()
         self.__publisher.destroy_when_not_in_use()

rclpy/rclpy/subscription.py

@@ -86,6 +86,12 @@ def handle(self):
         return self.__subscription
 
     def destroy(self):
+        """
+        Destroy a container for a ROS subscription.
+
+        .. warning:: Users should not destroy a subscription with this method, instead they
+           should call :meth:`.Node.destroy_subscription`.
+        """
         for handler in self.event_handlers:
             handler.destroy()
         self.handle.destroy_when_not_in_use()