add open/close abstract methods, fixes #39
diff --git a/serial/serialutil.py b/serial/serialutil.py
index ce0613c..a71b618 100644
--- a/serial/serialutil.py
+++ b/serial/serialutil.py
@@ -171,6 +171,16 @@
# - - - - - - - - - - - - - - - - - - - - - - - -
+ def open(self):
+ """Opens the Port"""
+ raise NotImplementedError("This function must be implemented in the subclass")
+
+ def close(self):
+ """Closes the Port"""
+ raise NotImplementedError("This function must be implemented in the subclass")
+
+ # - - - - - - - - - - - - - - - - - - - - - - - -
+
@property
def port(self):
"""\