returns a permission bit of the string permission value for the specified object type

def getPermissionBit(self, t, m):
        '''
        returns a permission bit of the string permission value for the specified object type
        '''
        try:
            if isinstance(m, string_types):
                return self.rights[t][m]['BITS']
            else:
                return m
        except KeyError:
            raise CommandExecutionError((
                'No right "{0}".  It should be one of the following:  {1}')
                .format(m, ', '.join(self.rights[t])))