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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 add_self_source(self):
 """Add a source that refers to the catalog itself. For now this points to the Open Supernova Catalog by default. """

        return self.add_source(
            bibcode=self.catalog.OSC_BIBCODE,
            name=self.catalog.OSC_NAME,
            url=self.catalog.OSC_URL,
            secondary=True)