[pitivi] timeline: more documentation

[Edward Hervey <edwardrv src gnome org>]

commit 75a5ce2b4af3a8587328323858b69664b4c99ebd
Author: Edward Hervey <bilboed bilboed com>
Date:   Thu Apr 30 17:26:02 2009 +0200

    timeline: more documentation
---
 pitivi/timeline/timeline.py |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/pitivi/timeline/timeline.py b/pitivi/timeline/timeline.py
index ab27308..a633b03 100644
--- a/pitivi/timeline/timeline.py
+++ b/pitivi/timeline/timeline.py
@@ -347,6 +347,8 @@ class Link(object):
         self.earliest_object = None
         self.earliest_start = None
 
+    # Selection implementations
+
     def addTimelineObject(self, timeline_object):
         if timeline_object.link is not None:
             raise TimelineError()
@@ -381,6 +383,13 @@ class Link(object):
         timeline_object.link = None
 
     def join(self, other_link):
+        """
+        Joins this Link with another and returns the resulting link.
+
+        @type other_link: C{Link}
+        @postcondition: L{self} and L{other_link} must not be used after
+        calling this method !!
+        """
         new_link = Link()
 
         for timeline_object in list(self.timeline_objects):