Ref issue #98 Add a missing header file.
Ref issue #98 Add a missing header file.

yungyuc/solvcon,solvcon/solvcon,solvcon/solvcon,solvcon/solvcon,yungyuc/solvcon,solvcon/solvcon,solvcon/solvcon,solvcon/solvcon,yungyuc/solvcon,yungyuc/solvcon,yungyuc/solvcon,yungyuc/solvcon