Our verification techniques turned out to be effective in
practice. In Table 2 we report the number of bugs we found
using our approach. For each class of bugs we were able
to re-discover bugs already reported (the Old columns) as
well as new bugs that have not been reported yet (the New
columns). For assurance, we took each event sequence our
approach has found automatically and played it manually,
through GUI interaction, to make sure the bug can actually
be reproduced in practice. We have reported the new bugs to
the developers; two of the bugs have been confirmed, while
others are in the process of confirmation.