Function StartsWith

tutorials/external/catch.hpp:4435–4436

            Contains( NSString* substr ){ return Impl::NSStringMatchers::Contains( substr ); }

        inline Impl::NSStringMatchers::StartsWith
            StartsWith( NSString* substr ){ return Impl::NSStringMatchers::StartsWith( substr ); }

        inline Impl::NSStringMatchers::EndsWith
            EndsWith( NSString* substr ){ return Impl::NSStringMatchers::EndsWith( substr ); }