Method toStringSuffix

tests/catch.h:1056–1061

            }
            std::string toStringSuffix() const
            {
                return m_caseSensitivity == CaseSensitive::No
                    ? " (case insensitive)"
                    : "";
            }
            CaseSensitive::Choice m_caseSensitivity;
            std::string m_str;
        };