Ad resolvers

if (resource.metadata != null) {
    if (resource.metadata.containsKey(DefaultMetadataKeys.CUSTOM_DELETE_RANGES_METADATA_KEY)
            || resource.metadata.containsKey(DefaultMetadataKeys.CUSTOM_REPLACE_RANGES_METADATA_KEY)
            || resource.metadata.containsKey(DefaultMetadataKeys.CUSTOM_AD_MARKERS_METADATA_KEY))
    {
        // Use the CustomRangesOpportunityGenerator for custom ranges opportunities
        result.push(new CustomRangesOpportunityGenerator());
        if (resource.metadata.containsKey(DefaultMetadataKeys.CUSTOM_DELETE_RANGES_METADATA_KEY))  {
            result.push(new AdSignalingModeOpportunityGenerator());
            // Manifest cue mode ignores replace range
            result.push(new SpliceOutOpportunityGenerator());
        }
        return result;
    }
}