From 7354b154bb5711a6341e75714d04ad52c451a043 Mon Sep 17 00:00:00 2001
From: Denis Demidov <dennis.demidov@gmail.com>
Date: Sat, 7 Nov 2015 14:45:50 +0300
Subject: [PATCH] Add dummy implementation for ButtonBase.buttons_pressed

Fixes #77
---
 ev3dev/core.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ev3dev/core.py b/ev3dev/core.py
index 2ea64aa..5fdd786 100644
--- a/ev3dev/core.py
+++ b/ev3dev/core.py
@@ -1733,6 +1733,10 @@ def process(self):
         if self.on_change is not None and state_diff:
             self.on_change([(button, button in new_state) for button in state_diff])
 
+    @property
+    def buttons_pressed(self):
+        raise NotImplementedError()
+
 
 class ButtonEVIO(ButtonBase):