fix bug in _add_sequence that only returned last result
fix bug in _add_sequence that only returned last result

nikken1/patentprocessor,nikken1/patentprocessor,funginstitute/patentprocessor,nikken1/patentprocessor,funginstitute/patentprocessor,yngcan/patentprocessor,yngcan/patentprocessor,yngcan/patentprocessor,funginstitute/patentprocessor