Currently, e.g. the `PostgreSQLQueryProcessor` (this applies to all `QueryProcessors`) immediately executes `process_query` when a `query` parameter is parsed. This is unexpcted and should be changed, so it always works as follows: a) ``` qp = PostgreSQLQueryProcessor() qp.set_query(query) qp.process_query() ``` or b) ``` qp = PostgreSQLQueryProcessor(query=query) qp.process_query() ```