I am currently implementing the facetting in Examine 4.0.0-beta1. I'm using this function to get facet results for a specific field. I've checked and the field that I'm looking for does have a value.

public static ICollection<LuceneFacetModel> GetFacetValues(this ISearchResults results, string field)
    {
        return results.GetFacet(field)
              .Select(f => new LuceneFacetModel
              {
                  Count = (int)f.Value,
                  Id = f.Label
              })
              .ToList();
    }

However I get an error that

System.ArgumentNullException: 'Value cannot be null. Arg_ParamName_Name'

This is weird, since even when there are no facets you'd just want to return an empty list. I have registered the facet that I'm looking for by using this in my ConfigureNamedOptions implementation.

var facetsConfig = new FacetsConfig();

        facetsConfig.DimConfigs.Add(Defaults.ParkFields.RelatedFacilities, new FacetsConfig.DimConfig { IsMultiValued = true });

        // set facetFullText fields
        // Note: https://shazwazza.github.io/Examine/articles/configuration.html contains all facetable fields.
        options.FieldDefinitions.AddOrUpdate(new FieldDefinition(Defaults.ParkFields.RelatedFacilities, FieldDefinitionTypes.FacetFullText));

        options.FacetsConfig = facetsConfig;

Does anyone know why this code, while searching for the field Defaults.ParkFields.RelatedFacilities would throw this exception?