module Transform: sigval string_to_item : ?filename:string ->
       tags:Biocaml_gff.Tags.t ->
       unit ->
       (string, (Biocaml_gff.item, [> Biocaml_gff.Error.parsing ]) Core.Result.t)
       Biocaml_transform.tBiocaml_transform.t for a given version.val item_to_string : tags:Biocaml_gff.Tags.t ->
       unit -> (Biocaml_gff.item, string) Biocaml_transform.tend