def _gen_back(self):
        '''
        Return a list of loaded roster backends
        '''
        back = set()
        if self.backends:
            for backend in self.backends:
                fun = '{0}.targets'.format(backend)
                if fun in self.rosters:
                    back.add(backend)
            return back
        return sorted(back)
def _gen_back ( self ) : back = set ( ) if self . backends : for backend in self . backends : fun = '{0}.targets' . format ( backend ) if fun in self . rosters : back . add ( backend ) return back return sorted ( back )
Return a list of loaded roster backends