public static Nest.TextPropertyDescriptor <T> AddKeywordField <T>(this Nest.TextPropertyDescriptor <T> descriptor) where T : class
 {
     return(descriptor.Fields(f => f.Keyword(s => s.Name("keyword").IgnoreAbove(256))));
 }
 public static Nest.TextPropertyDescriptor <T> AddKeywordAndSortFields <T>(this Nest.TextPropertyDescriptor <T> descriptor, string sortNormalizer) where T : class
 {
     return(descriptor.Fields(f => f.Keyword(s => s.Name("keyword").IgnoreAbove(256)).Keyword(s => s.Name("sort").Normalizer(sortNormalizer).IgnoreAbove(256))));
 }