public void NpgsqlCircleConstructorTest()
        {
            SqlExpression circle = SqlDml.Native("circle'<(0,1),10>'");

            CheckEquality(
                PostgresqlSqlDml.NpgsqlCircleConstructor(
                    PostgresqlSqlDml.NpgsqlPointConstructor(0, 1),
                    10),
                circle);

            CheckEquality(
                PostgresqlSqlDml.NpgsqlCircleConstructor(
                    SqlDml.Native("point'(0,1)'"),
                    10),
                circle);
        }
        public void NpgsqlBoxConstructorTest()
        {
            SqlExpression box = SqlDml.Native("box'(2,3),(0,1)'");

            CheckEquality(
                PostgresqlSqlDml.NpgsqlBoxConstructor(
                    PostgresqlSqlDml.NpgsqlPointConstructor(2, 3),
                    PostgresqlSqlDml.NpgsqlPointConstructor(0, 1)),
                box);

            CheckEquality(
                PostgresqlSqlDml.NpgsqlBoxConstructor(
                    SqlDml.Native("point'(2,3)'"),
                    SqlDml.Native("point'(0,1)'")),
                box);
        }
        public void NpgsqlLSegConstructorTest()
        {
            SqlExpression lSeg = SqlDml.Native("lseg'[(0,1),(2,3)]'");

            CheckEquality(
                PostgresqlSqlDml.NpgsqlLSegConstructor(
                    PostgresqlSqlDml.NpgsqlPointConstructor(0, 1),
                    PostgresqlSqlDml.NpgsqlPointConstructor(2, 3)),
                lSeg);

            CheckEquality(
                PostgresqlSqlDml.NpgsqlLSegConstructor(
                    SqlDml.Native("point'(0,1)'"),
                    SqlDml.Native("point'(2,3)'")),
                lSeg);
        }
        public void NpgsqlPointConstructorTest()
        {
            SqlExpression point = SqlDml.Native("point'(0,1)'");

            CheckInequality(PostgresqlSqlDml.NpgsqlPointConstructor(2, 3), point);
        }