def new_wildcards(self, job):
    'Return wildcards that are newly introduced in this job,\n        compared to its ancestors.'
    new_wildcards = set(job.wildcards.items())
    for job_ in self.dependencies[job]:
        if (not new_wildcards):
            return set()
        for wildcard in job_.wildcards.items():
            new_wildcards.discard(wildcard)
    return new_wildcards
Return wildcards that are newly introduced in this job,
compared to its ancestors.
def new_wildcards(self, job):
    'Return wildcards that are newly introduced in this job,\n        compared to its ancestors.'
    new_wildcards = set(job.wildcards.items())
    for job_ in self.dependencies[job]:
        if (not new_wildcards):
            return set()
        for wildcard in job_.wildcards.items():
            new_wildcards.discard(wildcard)
    return new_wildcards