anchor.diff:  type IntField() = 
       static member Default = new IntField() :> IField
       interface IField with
  -        member __.IsMultiField = false
           member __.FieldType = FlexSearch.Api.Constants.FieldType.Int
           member __.LuceneFieldType = IntFieldExtensions.LuceneFieldType
           member __.SortFieldType = IntFieldExtensions.SortFieldType
  
positive.code: [<Interface>]
  type IField = 
      
      /// Signifies if a field is represented using multiple fields in the index
      abstract IsMultiField : bool
      
      abstract Suffix : string option
      abstract SubTypes : IField [] option
  
negative.code:     /// Returns the Sort field associated with the field
      let sortField (schema : FieldSchema) = schema.Field.SortFieldType
  
      /// Signifies if a field is represented using multiple fields in the index
      let hasSubType (field : IField) = field.SubTypes.IsSome
  
  [<CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
  module TypeIndentity = 
      /// Generate the identity value from the given array
  