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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 __priority(self, pr, repo, pkg):
 """Add packages in blacklist by priority """

        if (pr[0] == repo and pr[1].startswith("*") and
                pr[1].endswith("*")):
            if pr[1][1:-1] in pkg:
                self.black.append(self.__add(repo, pkg))
        elif pr[0] == repo and pr[1].endswith("*"):
            if pkg.startswith(pr[1][:-1]):
                self.black.append(self.__add(repo, pkg))
        elif pr[0] == repo and pr[1].startswith("*"):
            if pkg.endswith(pr[1][1:]):
                self.black.append(self.__add(repo, pkg))
        elif pr[0] == repo and "*" not in pr[1]:
            self.black.append(self.__add(repo, pkg))