Radarr/src/NzbDrone.Api/Config/IndexerConfigModule.cs

using FluentValidation;
using NzbDrone.Core.Configuration;

namespace NzbDrone.Api.Config
{
    public class IndexerConfigModule : NzbDroneConfigModule<IndexerConfigResource>
    {

        public IndexerConfigModule(IConfigService configService)
            : base(configService)
        {
            SharedValidator.RuleFor(c => c.RssSyncInterval)
                .InclusiveBetween(10, 120)
                .When(c => c.RssSyncInterval > 0);
        }
    }
}