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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 get_foreign_key_declaration_sql(self, foreign_key):
 """ Obtain DBMS specific SQL code portion needed to set the FOREIGN KEY constraint of a field declaration to be used in statements like CREATE TABLE. :param foreign_key: The foreign key :type foreign_key: ForeignKeyConstraint :rtype: str """

        sql = self.get_foreign_key_base_declaration_sql(foreign_key)
        sql += self.get_advanced_foreign_key_options_sql(foreign_key)

        return sql