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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 revoke_all(cls, cur, schema_name, roles):
 """ Revoke all privileges from schema, tables, sequences and functions for a specific role """

        cur.execute('REVOKE ALL ON SCHEMA {0} FROM {1};'
                    'REVOKE ALL ON ALL TABLES IN SCHEMA {0} FROM {1};'
                    'REVOKE ALL ON ALL SEQUENCES IN SCHEMA {0} FROM {1};'
                    'REVOKE ALL ON ALL FUNCTIONS IN SCHEMA {0} FROM {1};'.format(schema_name, roles))