def diff(self):
        """
        Returns a subset of the rows, containing only the rows where results
        differ between the builds.
        """
        if self.__diff__ is not None:
            return self.__diff__

        d = OrderedDict()
        for test, results in self.results.items():
            previous = None
            for build in self.builds:
                current = [results.get((build, e)) for e in self.environments[build]]
                if previous and previous != current:
                    d[test] = results
                    break
                previous = current

        self.__diff__ = d
        return self.__diff__
def diff ( self ) : if self . __diff__ is not None : return self . __diff__ d = OrderedDict ( ) for test , results in self . results . items ( ) : previous = None for build in self . builds : current = [ results . get ( ( build , e ) ) for e in self . environments [ build ] ] if previous and previous != current : d [ test ] = results break previous = current self . __diff__ = d return self . __diff__
Returns a subset of the rows, containing only the rows where results
        differ between the builds.