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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 fixchars(self):
 """Replace characters or strings within subtitle file."""

        for key in Config.CHARFIXES:
            self.project.set_search_string(key)
            self.project.set_search_replacement(Config.CHARFIXES[key])
            self.project.replace_all()