Added null check, make sure empty list comes out.
Added null check, make sure empty list comes out.

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