def parse_vars(self, args):
        """
        Given variables like ``['a=b', 'c=d']`` turns it into ``{'a':
        'b', 'c': 'd'}``
        """
        result = {}
        for arg in args:
            if '=' not in arg:
                raise ValueError(
                    'Variable assignment %r invalid (no "=")'
                    % arg)
            name, value = arg.split('=', 1)
            result[name] = value
        return result