using the .Net Sdk

i am not seeing the update metdata for a file  

those are the fileds 

        public const string FieldSequence = "sequence_id";
        public const string FieldEtag = "etag";
        public const string FieldName = "name";
        public const string FieldCreatedAt = "created_at";
        public const string FieldModifiedAt = "modified_at";
        public const string FieldDescription = "description";
        public const string FieldSize = "size";
        public const string FieldPathCollection = "path_collection";
        public const string FieldCreatedBy = "created_by";
        public const string FieldModifiedBy = "modified_by";
        public const string FieldOwnedBy = "owned_by";
        public const string FieldSharedLink = "shared_link";
        public const string FieldParent = "parent";
        public const string FieldItemStatus = "item_status";
        public const string FieldPermissions = "permissions";
        public const string FieldTags = "tags";

Am I missing something or is this field never returned? From the developer api, it shows that this field exists 

so only from the api i will get all the fields?