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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 convert_association(self, association: Association) -> Entity: """ 'id' is already `join`ed in both the Association and the Entity, so we don't have to worry about what that looks like. We assume it's correct. """

        if "header" not in association or association["header"] == False:
            # print(json.dumps(association, indent=4))
            gpi_obj = {
                'id': association["subject"]["id"],
                'label': association["subject"]["label"],  # db_object_symbol,
                'full_name': association["subject"]["fullname"],  # db_object_name,
                'synonyms': association["subject"]["synonyms"],
                'type': association["subject"]["type"], #db_object_type,
                'parents': "", # GAF does not have this field, but it's optional in GPI
                'xrefs': "", # GAF does not have this field, but it's optional in GPI
                'taxon': {
                    'id': association["subject"]["taxon"]["id"]
                }
            }
            return Entity(gpi_obj)

        return None