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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def minus(repo_list_a, repo_list_b):
 """Method to create a list of repositories such that the repository belongs to repo list a but not repo list b. In an ideal scenario we should be able to do this by set(a) - set(b) but as GithubRepositories have shown that set() on them is not reliable resort to this until it is all sorted out. :param repo_list_a: List of repositories. :param repo_list_b: List of repositories. """

        included = defaultdict(lambda: False)

        for repo in repo_list_b:
            included[repo.full_name] = True

        a_minus_b = list()
        for repo in repo_list_a:
            if not included[repo.full_name]:
                included[repo.full_name] = True
                a_minus_b.append(repo)

        return a_minus_b