Add tests for block printing string.
Add tests for block printing string.

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