private void Assert(AstFilter result, string path, BsonValue divisor, BsonValue remainder)
        {
            var fieldOperationFilter = result.Should().BeOfType <AstFieldOperationFilter>().Subject;

            fieldOperationFilter.Field.Path.Should().Be(path);
            var modFilterOperation = fieldOperationFilter.Operation.Should().BeOfType <AstModFilterOperation>().Subject;

            modFilterOperation.Divisor.Should().Be(divisor);
            modFilterOperation.Remainder.Should().Be(remainder);
        }