// handle download and its options
func streamDownload(ctx context.Context, n *node.Node, options map[string]string) {
nf, err := n.FileReader()
defer nf.Close()
if err != nil {
// File not found or some sort of file read error.
// Probably deserves more checking
err_msg := "err:@preAuth node.FileReader: " + err.Error()
logger.Error(err_msg)
responder.RespondWithError(ctx, 500, err_msg)
return
}
// set defaults
filename := n.Id
var filterFunc filter.FilterFunc = nil
var compressionFormat string = ""
// use options if exist
if fn, has := options["filename"]; has {
filename = fn
}
if fl, has := options["filter"]; has {
if filter.Has(fl) {
filterFunc = filter.Filter(fl)
}
}
if cp, has := options["compression"]; has {
if archive.IsValidCompress(cp) {
compressionFormat = cp
}
}
// stream it
s := &request.Streamer{R: []file.SectionReader{nf}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Size: n.File.Size, Filter: filterFunc, Compression: compressionFormat}
err = s.Stream(false)
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@preAuth: s.stream: " + err.Error()
logger.Error(err_msg)
responder.RespondWithError(ctx, 500, err_msg)
}
return
}
// GET: /node/{id}
func (cr *NodeController) Read(id string, ctx context.Context) error {
u, err := request.Authenticate(ctx.HttpRequest())
if err != nil && err.Error() != e.NoAuth {
return request.AuthError(err, ctx)
}
// Fake public user
if u == nil {
if conf.Bool(conf.Conf["anon-read"]) {
u = &user.User{Uuid: ""}
} else {
return responder.RespondWithError(ctx, http.StatusUnauthorized, e.NoAuth)
}
}
// Load node and handle user unauthorized
n, err := node.Load(id, u.Uuid)
if err != nil {
if err.Error() == e.UnAuth {
return responder.RespondWithError(ctx, http.StatusUnauthorized, e.UnAuth)
} else if err.Error() == e.MongoDocNotFound {
return responder.RespondWithError(ctx, http.StatusNotFound, "Node not found")
} else {
// In theory the db connection could be lost between
// checking user and load but seems unlikely.
logger.Error("Err@node_Read:LoadNode:" + id + ":" + err.Error())
n, err = node.LoadFromDisk(id)
if err.Error() == "Node does not exist" {
logger.Error(err.Error())
return responder.RespondWithError(ctx, http.StatusBadRequest, err.Error())
} else if err != nil {
err_msg := "Err@node_Read:LoadNodeFromDisk:" + id + ":" + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
}
}
// Gather query params
query := ctx.HttpRequest().URL.Query()
var fFunc filter.FilterFunc = nil
if _, ok := query["filter"]; ok {
if filter.Has(query.Get("filter")) {
fFunc = filter.Filter(query.Get("filter"))
}
}
// Switch though param flags
// ?download=1 or ?download_raw=1
_, download_raw := query["download_raw"]
if _, ok := query["download"]; ok || download_raw {
if !n.HasFile() {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Node has no file")
}
filename := n.Id
if _, ok := query["filename"]; ok {
filename = query.Get("filename")
}
_, seek_ok := query["seek"]
if _, length_ok := query["length"]; seek_ok || length_ok {
if n.Type == "subset" {
return responder.RespondWithError(ctx, http.StatusBadRequest, "subset nodes do not currently support seek/length offset retrieval")
}
var seek int64
var length int64
if !seek_ok {
seek = 0
length_str := query.Get("length")
length, err = strconv.ParseInt(length_str, 10, 0)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "length must be an integer value")
}
} else if !length_ok {
seek_str := query.Get("seek")
seek, err = strconv.ParseInt(seek_str, 10, 0)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "seek must be an integer value")
}
length = n.File.Size - seek
} else {
seek_str := query.Get("seek")
seek, err = strconv.ParseInt(seek_str, 10, 0)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "seek must be an integer value")
}
length_str := query.Get("length")
length, err = strconv.ParseInt(length_str, 10, 0)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "length must be an integer value")
}
}
r, err := n.FileReader()
defer r.Close()
if err != nil {
err_msg := "Err@node_Read:Open: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
s := &request.Streamer{R: []file.SectionReader{}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Size: length, Filter: fFunc}
s.R = append(s.R, io.NewSectionReader(r, seek, length))
if download_raw {
err = s.StreamRaw()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.StreamRaw: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
} else {
err = s.Stream()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.Stream: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
}
} else if _, ok := query["index"]; ok {
//handling bam file
if query.Get("index") == "bai" {
if n.Type == "subset" {
return responder.RespondWithError(ctx, http.StatusBadRequest, "subset nodes do not support bam indices")
}
s := &request.Streamer{R: []file.SectionReader{}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Size: n.File.Size, Filter: fFunc}
var region string
if _, ok := query["region"]; ok {
//retrieve alingments overlapped with specified region
region = query.Get("region")
}
argv, err := request.ParseSamtoolsArgs(ctx)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invaid args in query url")
}
err = s.StreamSamtools(n.FilePath(), region, argv...)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "error while invoking samtools")
}
return nil
}
// open file
r, err := n.FileReader()
defer r.Close()
if err != nil {
err_msg := "Err@node_Read:Open: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
// load index obj and info
idxName := query.Get("index")
idxInfo, ok := n.Indexes[idxName]
if !ok {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index")
}
idx, err := n.DynamicIndex(idxName)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, err.Error())
}
if idx.Type() == "virtual" {
if n.Type == "subset" {
return responder.RespondWithError(ctx, http.StatusBadRequest, "subset nodes do not currently support virtual indices")
}
csize := conf.CHUNK_SIZE
if _, ok := query["chunk_size"]; ok {
csize, err = strconv.ParseInt(query.Get("chunk_size"), 10, 64)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid chunk_size")
}
}
idx.Set(map[string]interface{}{"ChunkSize": csize})
}
var size int64 = 0
s := &request.Streamer{R: []file.SectionReader{}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Filter: fFunc}
_, hasPart := query["part"]
if n.Type == "subset" && idxName == "chunkrecord" {
recordIdxName := "record"
recordIdxInfo, ok := n.Indexes[recordIdxName]
if !ok {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid request, record index must exist to retrieve chunkrecord index on a subset node.")
}
recordIdx, err := n.DynamicIndex(recordIdxName)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, err.Error())
}
if !hasPart {
// download full subset file
fullRange := "1-" + strconv.FormatInt(recordIdxInfo.TotalUnits, 10)
recSlice, err := recordIdx.Range(fullRange, n.IndexPath()+"/"+recordIdxName+".idx", recordIdxInfo.TotalUnits)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index subset")
}
for _, rec := range recSlice {
size += rec[1]
s.R = append(s.R, io.NewSectionReader(r, rec[0], rec[1]))
}
} else if hasPart {
// download parts
for _, p := range query["part"] {
chunkRecSlice, err := idx.Range(p, n.IndexPath()+"/"+idxName+".idx", idxInfo.TotalUnits)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index part")
}
// This gets us the parts of the chunkrecord index, but we still need to convert these to record indices.
for _, chunkRec := range chunkRecSlice {
start := (chunkRec[0] / 16) + 1
stop := (start - 1) + (chunkRec[1] / 16)
recSlice, err := recordIdx.Range(strconv.FormatInt(start, 10)+"-"+strconv.FormatInt(stop, 10), n.IndexPath()+"/"+recordIdxName+".idx", recordIdxInfo.TotalUnits)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index subset")
}
for _, rec := range recSlice {
size += rec[1]
s.R = append(s.R, io.NewSectionReader(r, rec[0], rec[1]))
}
}
}
} else {
// bad request
return responder.RespondWithError(ctx, http.StatusBadRequest, "Index parameter requires part parameter")
}
} else {
if (!hasPart) && (idxInfo.Type == "subset") {
// download full subset file
fullRange := "1-" + strconv.FormatInt(idxInfo.TotalUnits, 10)
recSlice, err := idx.Range(fullRange, n.IndexPath()+"/"+idxName+".idx", idxInfo.TotalUnits)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index subset")
}
for _, rec := range recSlice {
size += rec[1]
s.R = append(s.R, io.NewSectionReader(r, rec[0], rec[1]))
}
} else if hasPart {
// download parts
for _, p := range query["part"] {
// special case for subset ranges
if idxInfo.Type == "subset" {
recSlice, err := idx.Range(p, n.IndexPath()+"/"+idxName+".idx", idxInfo.TotalUnits)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index part")
}
for _, rec := range recSlice {
size += rec[1]
s.R = append(s.R, io.NewSectionReader(r, rec[0], rec[1]))
}
} else {
pos, length, err := idx.Part(p, n.IndexPath()+"/"+idxName+".idx", idxInfo.TotalUnits)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index part")
}
size += length
s.R = append(s.R, io.NewSectionReader(r, pos, length))
}
}
} else {
// bad request
return responder.RespondWithError(ctx, http.StatusBadRequest, "Index parameter requires part parameter")
}
}
s.Size = size
if download_raw {
err = s.StreamRaw()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.StreamRaw: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
} else {
err = s.Stream()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.Stream: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
}
// download full file
} else {
if n.Type == "subset" {
// open file
r, err := n.FileReader()
defer r.Close()
if err != nil {
err_msg := "Err@node_Read:Open: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
idx := index.New()
s := &request.Streamer{R: []file.SectionReader{}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Size: n.File.Size, Filter: fFunc}
fullRange := "1-" + strconv.FormatInt(n.Subset.Index.TotalUnits, 10)
recSlice, err := idx.Range(fullRange, n.Path()+"/"+n.Id+".subset.idx", n.Subset.Index.TotalUnits)
if err != nil {
return responder.RespondWithError(ctx, http.StatusInternalServerError, "Invalid data index for subset node.")
}
for _, rec := range recSlice {
s.R = append(s.R, io.NewSectionReader(r, rec[0], rec[1]))
}
if download_raw {
err = s.StreamRaw()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.StreamRaw: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
} else {
err = s.Stream()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.Stream: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
}
} else {
nf, err := n.FileReader()
defer nf.Close()
if err != nil {
// File not found or some sort of file read error.
// Probably deserves more checking
err_msg := "err:@node_Read node.FileReader: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
s := &request.Streamer{R: []file.SectionReader{nf}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Size: n.File.Size, Filter: fFunc}
if download_raw {
err = s.StreamRaw()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.StreamRaw: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
} else {
err = s.Stream()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.Stream: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
}
}
}
} else if _, ok := query["download_url"]; ok {
if n.Type == "subset" {
return responder.RespondWithError(ctx, http.StatusBadRequest, "subset nodes do not currently support download_url operation")
}
if !n.HasFile() {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Node has no file")
} else {
options := map[string]string{}
if _, ok := query["filename"]; ok {
options["filename"] = query.Get("filename")
}
if p, err := preauth.New(util.RandString(20), "download", n.Id, options); err != nil {
err_msg := "err:@node_Read download_url: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
} else {
return responder.RespondWithData(ctx, util.UrlResponse{Url: util.ApiUrl(ctx) + "/preauth/" + p.Id, ValidTill: p.ValidTill.Format(time.ANSIC)})
}
}
} else if _, ok := query["download_post"]; ok {
// This is a request to post the node to another Shock server. The 'post_url' parameter is required.
// By default the post operation will include the data file and attributes (these options can be set
// with post_data=0/1 and post_attr=0/1).
if n.Type == "subset" {
return responder.RespondWithError(ctx, http.StatusBadRequest, "subset nodes do not currently support download_post operation")
}
post_url := ""
if _, ok := query["post_url"]; ok {
post_url = query.Get("post_url")
} else {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Request type requires post_url parameter of where to post new Shock node")
}
post_opts := map[string]int{
"post_data": 1,
"post_attr": 1,
}
for k, _ := range post_opts {
if _, ok := query[k]; ok {
if query.Get(k) == "0" {
post_opts[k] = 0
} else if query.Get(k) == "1" {
post_opts[k] = 1
} else {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Parameter "+k+" must be either 0 or 1")
}
}
}
form := client.NewForm()
form.AddParam("file_name", n.File.Name)
if post_opts["post_data"] == 1 {
form.AddFile("upload", n.FilePath())
}
if post_opts["post_attr"] == 1 && n.Attributes != nil {
attr, _ := json.Marshal(n.Attributes)
form.AddParam("attributes_str", string(attr[:]))
}
err = form.Create()
if err != nil {
err_msg := "could not create multipart form for posting to Shock server: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
headers := client.Header{
"Content-Type": form.ContentType,
"Content-Length": strconv.FormatInt(form.Length, 10),
}
if _, hasAuth := ctx.HttpRequest().Header["Authorization"]; hasAuth {
headers["Authorization"] = ctx.HttpRequest().Header.Get("Authorization")
}
if res, err := client.Do("POST", post_url, headers, form.Reader); err == nil {
if res.StatusCode == 200 {
r := responseWrapper{}
body, _ := ioutil.ReadAll(res.Body)
if err = json.Unmarshal(body, &r); err != nil {
err_msg := "err:@node_Read POST: " + err.Error()
logger.Error(err_msg)
return responder.WriteResponseObject(ctx, http.StatusInternalServerError, err_msg)
} else {
return responder.WriteResponseObject(ctx, http.StatusOK, r)
}
} else {
r := responseWrapper{}
body, _ := ioutil.ReadAll(res.Body)
if err = json.Unmarshal(body, &r); err == nil {
err_msg := res.Status + ": " + (*r.Error)[0]
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
} else {
err_msg := "request error: " + res.Status
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
}
} else {
return err
}
} else {
// Base case respond with node in json
return responder.RespondWithData(ctx, n)
}
return nil
}
// GET: /node/{id}
func (cr *NodeController) Read(id string, ctx context.Context) error {
u, err := request.Authenticate(ctx.HttpRequest())
if err != nil && err.Error() != e.NoAuth {
return request.AuthError(err, ctx)
}
// Fake public user
if u == nil {
if conf.Bool(conf.Conf["anon-read"]) {
u = &user.User{Uuid: ""}
} else {
return responder.RespondWithError(ctx, http.StatusUnauthorized, e.NoAuth)
}
}
// Gather query params
query := ctx.HttpRequest().URL.Query()
var fFunc filter.FilterFunc = nil
if _, ok := query["filter"]; ok {
if filter.Has(query.Get("filter")) {
fFunc = filter.Filter(query.Get("filter"))
}
}
// Load node and handle user unauthorized
n, err := node.Load(id, u.Uuid)
if err != nil {
if err.Error() == e.UnAuth {
return responder.RespondWithError(ctx, http.StatusUnauthorized, e.UnAuth)
} else if err.Error() == e.MongoDocNotFound {
return responder.RespondWithError(ctx, http.StatusNotFound, "Node not found")
} else {
// In theory the db connection could be lost between
// checking user and load but seems unlikely.
logger.Error("Err@node_Read:LoadNode:" + id + ":" + err.Error())
n, err = node.LoadFromDisk(id)
if err != nil {
err_msg := "Err@node_Read:LoadNodeFromDisk:" + id + ":" + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
}
}
// Switch though param flags
// ?download=1
if _, ok := query["download"]; ok {
if !n.HasFile() {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Node has no file")
}
filename := n.Id
if _, ok := query["filename"]; ok {
filename = query.Get("filename")
}
if _, ok := query["index"]; ok {
//handling bam file
if query.Get("index") == "bai" {
s := &request.Streamer{R: []file.SectionReader{}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Size: n.File.Size, Filter: fFunc}
var region string
if _, ok := query["region"]; ok {
//retrieve alingments overlapped with specified region
region = query.Get("region")
}
argv, err := request.ParseSamtoolsArgs(ctx)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invaid args in query url")
}
err = s.StreamSamtools(n.FilePath(), region, argv...)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "error while involking samtools")
}
return nil
}
// if forgot ?part=N
if _, ok := query["part"]; !ok {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Index parameter requires part parameter")
}
// open file
r, err := n.FileReader()
defer r.Close()
if err != nil {
err_msg := "Err@node_Read:Open: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
}
// load index
idx, err := n.Index(query.Get("index"))
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index")
}
if idx.Type() == "virtual" {
csize := conf.CHUNK_SIZE
if _, ok := query["chunk_size"]; ok {
csize, err = strconv.ParseInt(query.Get("chunk_size"), 10, 64)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid chunk_size")
}
}
idx.Set(map[string]interface{}{"ChunkSize": csize})
}
var size int64 = 0
s := &request.Streamer{R: []file.SectionReader{}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Filter: fFunc}
for _, p := range query["part"] {
pos, length, err := idx.Part(p)
if err != nil {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Invalid index part")
}
size += length
s.R = append(s.R, io.NewSectionReader(r, pos, length))
}
s.Size = size
err = s.Stream()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read s.stream: " + err.Error()
logger.Error(err_msg)
responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
} else {
nf, err := n.FileReader()
defer nf.Close()
if err != nil {
// File not found or some sort of file read error.
// Probably deserves more checking
err_msg := "err:@node_Read node.FileReader: " + err.Error()
logger.Error(err_msg)
return responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
s := &request.Streamer{R: []file.SectionReader{nf}, W: ctx.HttpResponseWriter(), ContentType: "application/octet-stream", Filename: filename, Size: n.File.Size, Filter: fFunc}
err = s.Stream()
if err != nil {
// causes "multiple response.WriteHeader calls" error but better than no response
err_msg := "err:@node_Read: s.stream: " + err.Error()
logger.Error(err_msg)
responder.RespondWithError(ctx, http.StatusBadRequest, err_msg)
}
}
} else if _, ok := query["download_url"]; ok {
if !n.HasFile() {
return responder.RespondWithError(ctx, http.StatusBadRequest, "Node has not file")
} else if u.Uuid == "" {
return responder.RespondWithError(ctx, http.StatusUnauthorized, e.NoAuth)
} else {
options := map[string]string{}
if _, ok := query["filename"]; ok {
options["filename"] = query.Get("filename")
}
if p, err := preauth.New(util.RandString(20), "download", n.Id, options); err != nil {
err_msg := "err:@node_Read download_url: " + err.Error()
logger.Error(err_msg)
responder.RespondWithError(ctx, http.StatusInternalServerError, err_msg)
} else {
responder.RespondWithData(ctx, util.UrlResponse{Url: util.ApiUrl(ctx) + "/preauth/" + p.Id, ValidTill: p.ValidTill.Format(time.ANSIC)})
}
}
} else {
// Base case respond with node in json
responder.RespondWithData(ctx, n)
}
return nil
}