github.com/dotlike13/wemix30_go@v1.8.23/swarm/api/client/client_test.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package client
    18  
    19  import (
    20  	"bytes"
    21  	"io/ioutil"
    22  	"os"
    23  	"path/filepath"
    24  	"reflect"
    25  	"sort"
    26  	"testing"
    27  
    28  	"github.com/ethereum/go-ethereum/swarm/storage"
    29  	"github.com/ethereum/go-ethereum/swarm/storage/feed/lookup"
    30  
    31  	"github.com/ethereum/go-ethereum/common"
    32  	"github.com/ethereum/go-ethereum/crypto"
    33  	"github.com/ethereum/go-ethereum/swarm/api"
    34  	swarmhttp "github.com/ethereum/go-ethereum/swarm/api/http"
    35  	"github.com/ethereum/go-ethereum/swarm/storage/feed"
    36  )
    37  
    38  func serverFunc(api *api.API) swarmhttp.TestServer {
    39  	return swarmhttp.NewServer(api, "")
    40  }
    41  
    42  // TestClientUploadDownloadRaw test uploading and downloading raw data to swarm
    43  func TestClientUploadDownloadRaw(t *testing.T) {
    44  	testClientUploadDownloadRaw(false, t)
    45  }
    46  func TestClientUploadDownloadRawEncrypted(t *testing.T) {
    47  	testClientUploadDownloadRaw(true, t)
    48  }
    49  
    50  func testClientUploadDownloadRaw(toEncrypt bool, t *testing.T) {
    51  	srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
    52  	defer srv.Close()
    53  
    54  	client := NewClient(srv.URL)
    55  
    56  	// upload some raw data
    57  	data := []byte("foo123")
    58  	hash, err := client.UploadRaw(bytes.NewReader(data), int64(len(data)), toEncrypt)
    59  	if err != nil {
    60  		t.Fatal(err)
    61  	}
    62  
    63  	// check we can download the same data
    64  	res, isEncrypted, err := client.DownloadRaw(hash)
    65  	if err != nil {
    66  		t.Fatal(err)
    67  	}
    68  	if isEncrypted != toEncrypt {
    69  		t.Fatalf("Expected encyption status %v got %v", toEncrypt, isEncrypted)
    70  	}
    71  	defer res.Close()
    72  	gotData, err := ioutil.ReadAll(res)
    73  	if err != nil {
    74  		t.Fatal(err)
    75  	}
    76  	if !bytes.Equal(gotData, data) {
    77  		t.Fatalf("expected downloaded data to be %q, got %q", data, gotData)
    78  	}
    79  }
    80  
    81  // TestClientUploadDownloadFiles test uploading and downloading files to swarm
    82  // manifests
    83  func TestClientUploadDownloadFiles(t *testing.T) {
    84  	testClientUploadDownloadFiles(false, t)
    85  }
    86  
    87  func TestClientUploadDownloadFilesEncrypted(t *testing.T) {
    88  	testClientUploadDownloadFiles(true, t)
    89  }
    90  
    91  func testClientUploadDownloadFiles(toEncrypt bool, t *testing.T) {
    92  	srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
    93  	defer srv.Close()
    94  
    95  	client := NewClient(srv.URL)
    96  	upload := func(manifest, path string, data []byte) string {
    97  		file := &File{
    98  			ReadCloser: ioutil.NopCloser(bytes.NewReader(data)),
    99  			ManifestEntry: api.ManifestEntry{
   100  				Path:        path,
   101  				ContentType: "text/plain",
   102  				Size:        int64(len(data)),
   103  			},
   104  		}
   105  		hash, err := client.Upload(file, manifest, toEncrypt)
   106  		if err != nil {
   107  			t.Fatal(err)
   108  		}
   109  		return hash
   110  	}
   111  	checkDownload := func(manifest, path string, expected []byte) {
   112  		file, err := client.Download(manifest, path)
   113  		if err != nil {
   114  			t.Fatal(err)
   115  		}
   116  		defer file.Close()
   117  		if file.Size != int64(len(expected)) {
   118  			t.Fatalf("expected downloaded file to be %d bytes, got %d", len(expected), file.Size)
   119  		}
   120  		if file.ContentType != "text/plain" {
   121  			t.Fatalf("expected downloaded file to have type %q, got %q", "text/plain", file.ContentType)
   122  		}
   123  		data, err := ioutil.ReadAll(file)
   124  		if err != nil {
   125  			t.Fatal(err)
   126  		}
   127  		if !bytes.Equal(data, expected) {
   128  			t.Fatalf("expected downloaded data to be %q, got %q", expected, data)
   129  		}
   130  	}
   131  
   132  	// upload a file to the root of a manifest
   133  	rootData := []byte("some-data")
   134  	rootHash := upload("", "", rootData)
   135  
   136  	// check we can download the root file
   137  	checkDownload(rootHash, "", rootData)
   138  
   139  	// upload another file to the same manifest
   140  	otherData := []byte("some-other-data")
   141  	newHash := upload(rootHash, "some/other/path", otherData)
   142  
   143  	// check we can download both files from the new manifest
   144  	checkDownload(newHash, "", rootData)
   145  	checkDownload(newHash, "some/other/path", otherData)
   146  
   147  	// replace the root file with different data
   148  	newHash = upload(newHash, "", otherData)
   149  
   150  	// check both files have the other data
   151  	checkDownload(newHash, "", otherData)
   152  	checkDownload(newHash, "some/other/path", otherData)
   153  }
   154  
   155  var testDirFiles = []string{
   156  	"file1.txt",
   157  	"file2.txt",
   158  	"dir1/file3.txt",
   159  	"dir1/file4.txt",
   160  	"dir2/file5.txt",
   161  	"dir2/dir3/file6.txt",
   162  	"dir2/dir4/file7.txt",
   163  	"dir2/dir4/file8.txt",
   164  }
   165  
   166  func newTestDirectory(t *testing.T) string {
   167  	dir, err := ioutil.TempDir("", "swarm-client-test")
   168  	if err != nil {
   169  		t.Fatal(err)
   170  	}
   171  
   172  	for _, file := range testDirFiles {
   173  		path := filepath.Join(dir, file)
   174  		if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
   175  			os.RemoveAll(dir)
   176  			t.Fatalf("error creating dir for %s: %s", path, err)
   177  		}
   178  		if err := ioutil.WriteFile(path, []byte(file), 0644); err != nil {
   179  			os.RemoveAll(dir)
   180  			t.Fatalf("error writing file %s: %s", path, err)
   181  		}
   182  	}
   183  
   184  	return dir
   185  }
   186  
   187  // TestClientUploadDownloadDirectory tests uploading and downloading a
   188  // directory of files to a swarm manifest
   189  func TestClientUploadDownloadDirectory(t *testing.T) {
   190  	srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
   191  	defer srv.Close()
   192  
   193  	dir := newTestDirectory(t)
   194  	defer os.RemoveAll(dir)
   195  
   196  	// upload the directory
   197  	client := NewClient(srv.URL)
   198  	defaultPath := testDirFiles[0]
   199  	hash, err := client.UploadDirectory(dir, defaultPath, "", false)
   200  	if err != nil {
   201  		t.Fatalf("error uploading directory: %s", err)
   202  	}
   203  
   204  	// check we can download the individual files
   205  	checkDownloadFile := func(path string, expected []byte) {
   206  		file, err := client.Download(hash, path)
   207  		if err != nil {
   208  			t.Fatal(err)
   209  		}
   210  		defer file.Close()
   211  		data, err := ioutil.ReadAll(file)
   212  		if err != nil {
   213  			t.Fatal(err)
   214  		}
   215  		if !bytes.Equal(data, expected) {
   216  			t.Fatalf("expected data to be %q, got %q", expected, data)
   217  		}
   218  	}
   219  	for _, file := range testDirFiles {
   220  		checkDownloadFile(file, []byte(file))
   221  	}
   222  
   223  	// check we can download the default path
   224  	checkDownloadFile("", []byte(testDirFiles[0]))
   225  
   226  	// check we can download the directory
   227  	tmp, err := ioutil.TempDir("", "swarm-client-test")
   228  	if err != nil {
   229  		t.Fatal(err)
   230  	}
   231  	defer os.RemoveAll(tmp)
   232  	if err := client.DownloadDirectory(hash, "", tmp, ""); err != nil {
   233  		t.Fatal(err)
   234  	}
   235  	for _, file := range testDirFiles {
   236  		data, err := ioutil.ReadFile(filepath.Join(tmp, file))
   237  		if err != nil {
   238  			t.Fatal(err)
   239  		}
   240  		if !bytes.Equal(data, []byte(file)) {
   241  			t.Fatalf("expected data to be %q, got %q", file, data)
   242  		}
   243  	}
   244  }
   245  
   246  // TestClientFileList tests listing files in a swarm manifest
   247  func TestClientFileList(t *testing.T) {
   248  	testClientFileList(false, t)
   249  }
   250  
   251  func TestClientFileListEncrypted(t *testing.T) {
   252  	testClientFileList(true, t)
   253  }
   254  
   255  func testClientFileList(toEncrypt bool, t *testing.T) {
   256  	srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
   257  	defer srv.Close()
   258  
   259  	dir := newTestDirectory(t)
   260  	defer os.RemoveAll(dir)
   261  
   262  	client := NewClient(srv.URL)
   263  	hash, err := client.UploadDirectory(dir, "", "", toEncrypt)
   264  	if err != nil {
   265  		t.Fatalf("error uploading directory: %s", err)
   266  	}
   267  
   268  	ls := func(prefix string) []string {
   269  		list, err := client.List(hash, prefix, "")
   270  		if err != nil {
   271  			t.Fatal(err)
   272  		}
   273  		paths := make([]string, 0, len(list.CommonPrefixes)+len(list.Entries))
   274  		paths = append(paths, list.CommonPrefixes...)
   275  		for _, entry := range list.Entries {
   276  			paths = append(paths, entry.Path)
   277  		}
   278  		sort.Strings(paths)
   279  		return paths
   280  	}
   281  
   282  	tests := map[string][]string{
   283  		"":                    {"dir1/", "dir2/", "file1.txt", "file2.txt"},
   284  		"file":                {"file1.txt", "file2.txt"},
   285  		"file1":               {"file1.txt"},
   286  		"file2.txt":           {"file2.txt"},
   287  		"file12":              {},
   288  		"dir":                 {"dir1/", "dir2/"},
   289  		"dir1":                {"dir1/"},
   290  		"dir1/":               {"dir1/file3.txt", "dir1/file4.txt"},
   291  		"dir1/file":           {"dir1/file3.txt", "dir1/file4.txt"},
   292  		"dir1/file3.txt":      {"dir1/file3.txt"},
   293  		"dir1/file34":         {},
   294  		"dir2/":               {"dir2/dir3/", "dir2/dir4/", "dir2/file5.txt"},
   295  		"dir2/file":           {"dir2/file5.txt"},
   296  		"dir2/dir":            {"dir2/dir3/", "dir2/dir4/"},
   297  		"dir2/dir3/":          {"dir2/dir3/file6.txt"},
   298  		"dir2/dir4/":          {"dir2/dir4/file7.txt", "dir2/dir4/file8.txt"},
   299  		"dir2/dir4/file":      {"dir2/dir4/file7.txt", "dir2/dir4/file8.txt"},
   300  		"dir2/dir4/file7.txt": {"dir2/dir4/file7.txt"},
   301  		"dir2/dir4/file78":    {},
   302  	}
   303  	for prefix, expected := range tests {
   304  		actual := ls(prefix)
   305  		if !reflect.DeepEqual(actual, expected) {
   306  			t.Fatalf("expected prefix %q to return %v, got %v", prefix, expected, actual)
   307  		}
   308  	}
   309  }
   310  
   311  // TestClientMultipartUpload tests uploading files to swarm using a multipart
   312  // upload
   313  func TestClientMultipartUpload(t *testing.T) {
   314  	srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
   315  	defer srv.Close()
   316  
   317  	// define an uploader which uploads testDirFiles with some data
   318  	data := []byte("some-data")
   319  	uploader := UploaderFunc(func(upload UploadFn) error {
   320  		for _, name := range testDirFiles {
   321  			file := &File{
   322  				ReadCloser: ioutil.NopCloser(bytes.NewReader(data)),
   323  				ManifestEntry: api.ManifestEntry{
   324  					Path:        name,
   325  					ContentType: "text/plain",
   326  					Size:        int64(len(data)),
   327  				},
   328  			}
   329  			if err := upload(file); err != nil {
   330  				return err
   331  			}
   332  		}
   333  		return nil
   334  	})
   335  
   336  	// upload the files as a multipart upload
   337  	client := NewClient(srv.URL)
   338  	hash, err := client.MultipartUpload("", uploader)
   339  	if err != nil {
   340  		t.Fatal(err)
   341  	}
   342  
   343  	// check we can download the individual files
   344  	checkDownloadFile := func(path string) {
   345  		file, err := client.Download(hash, path)
   346  		if err != nil {
   347  			t.Fatal(err)
   348  		}
   349  		defer file.Close()
   350  		gotData, err := ioutil.ReadAll(file)
   351  		if err != nil {
   352  			t.Fatal(err)
   353  		}
   354  		if !bytes.Equal(gotData, data) {
   355  			t.Fatalf("expected data to be %q, got %q", data, gotData)
   356  		}
   357  	}
   358  	for _, file := range testDirFiles {
   359  		checkDownloadFile(file)
   360  	}
   361  }
   362  
   363  func newTestSigner() (*feed.GenericSigner, error) {
   364  	privKey, err := crypto.HexToECDSA("deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef")
   365  	if err != nil {
   366  		return nil, err
   367  	}
   368  	return feed.NewGenericSigner(privKey), nil
   369  }
   370  
   371  // Test the transparent resolving of feed updates with bzz:// scheme
   372  //
   373  // First upload data to bzz:, and store the Swarm hash to the resulting manifest in a feed update.
   374  // This effectively uses a feed to store a pointer to content rather than the content itself
   375  // Retrieving the update with the Swarm hash should return the manifest pointing directly to the data
   376  // and raw retrieve of that hash should return the data
   377  func TestClientBzzWithFeed(t *testing.T) {
   378  
   379  	signer, _ := newTestSigner()
   380  
   381  	// Initialize a Swarm test server
   382  	srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
   383  	swarmClient := NewClient(srv.URL)
   384  	defer srv.Close()
   385  
   386  	// put together some data for our test:
   387  	dataBytes := []byte(`
   388  	//
   389  	// Create some data our manifest will point to. Data that could be very big and wouldn't fit in a feed update.
   390  	// So what we are going to do is upload it to Swarm bzz:// and obtain a **manifest hash** pointing to it:
   391  	//
   392  	// MANIFEST HASH --> DATA
   393  	//
   394  	// Then, we store that **manifest hash** into a Swarm Feed update. Once we have done this,
   395  	// we can use the **feed manifest hash** in bzz:// instead, this way: bzz://feed-manifest-hash.
   396  	//
   397  	// FEED MANIFEST HASH --> MANIFEST HASH --> DATA
   398  	//
   399  	// Given that we can update the feed at any time with a new **manifest hash** but the **feed manifest hash**
   400  	// stays constant, we have effectively created a fixed address to changing content. (Applause)
   401  	//
   402  	// FEED MANIFEST HASH (the same) --> MANIFEST HASH(2) --> DATA(2)
   403  	//
   404  	`)
   405  
   406  	// Create a virtual File out of memory containing the above data
   407  	f := &File{
   408  		ReadCloser: ioutil.NopCloser(bytes.NewReader(dataBytes)),
   409  		ManifestEntry: api.ManifestEntry{
   410  			ContentType: "text/plain",
   411  			Mode:        0660,
   412  			Size:        int64(len(dataBytes)),
   413  		},
   414  	}
   415  
   416  	// upload data to bzz:// and retrieve the content-addressed manifest hash, hex-encoded.
   417  	manifestAddressHex, err := swarmClient.Upload(f, "", false)
   418  	if err != nil {
   419  		t.Fatalf("Error creating manifest: %s", err)
   420  	}
   421  
   422  	// convert the hex-encoded manifest hash to a 32-byte slice
   423  	manifestAddress := common.FromHex(manifestAddressHex)
   424  
   425  	if len(manifestAddress) != storage.AddressLength {
   426  		t.Fatalf("Something went wrong. Got a hash of an unexpected length. Expected %d bytes. Got %d", storage.AddressLength, len(manifestAddress))
   427  	}
   428  
   429  	// Now create a **feed manifest**. For that, we need a topic:
   430  	topic, _ := feed.NewTopic("interesting topic indeed", nil)
   431  
   432  	// Build a feed request to update data
   433  	request := feed.NewFirstRequest(topic)
   434  
   435  	// Put the 32-byte address of the manifest into the feed update
   436  	request.SetData(manifestAddress)
   437  
   438  	// Sign the update
   439  	if err := request.Sign(signer); err != nil {
   440  		t.Fatalf("Error signing update: %s", err)
   441  	}
   442  
   443  	// Publish the update and at the same time request a **feed manifest** to be created
   444  	feedManifestAddressHex, err := swarmClient.CreateFeedWithManifest(request)
   445  	if err != nil {
   446  		t.Fatalf("Error creating feed manifest: %s", err)
   447  	}
   448  
   449  	// Check we have received the exact **feed manifest** to be expected
   450  	// given the topic and user signing the updates:
   451  	correctFeedManifestAddrHex := "747c402e5b9dc715a25a4393147512167bab018a007fad7cdcd9adc7fce1ced2"
   452  	if feedManifestAddressHex != correctFeedManifestAddrHex {
   453  		t.Fatalf("Response feed manifest mismatch, expected '%s', got '%s'", correctFeedManifestAddrHex, feedManifestAddressHex)
   454  	}
   455  
   456  	// Check we get a not found error when trying to get feed updates with a made-up manifest
   457  	_, err = swarmClient.QueryFeed(nil, "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb")
   458  	if err != ErrNoFeedUpdatesFound {
   459  		t.Fatalf("Expected to receive ErrNoFeedUpdatesFound error. Got: %s", err)
   460  	}
   461  
   462  	// If we query the feed directly we should get **manifest hash** back:
   463  	reader, err := swarmClient.QueryFeed(nil, correctFeedManifestAddrHex)
   464  	if err != nil {
   465  		t.Fatalf("Error retrieving feed updates: %s", err)
   466  	}
   467  	defer reader.Close()
   468  	gotData, err := ioutil.ReadAll(reader)
   469  	if err != nil {
   470  		t.Fatal(err)
   471  	}
   472  
   473  	//Check that indeed the **manifest hash** is retrieved
   474  	if !bytes.Equal(manifestAddress, gotData) {
   475  		t.Fatalf("Expected: %v, got %v", manifestAddress, gotData)
   476  	}
   477  
   478  	// Now the final test we were looking for: Use bzz://<feed-manifest> and that should resolve all manifests
   479  	// and return the original data directly:
   480  	f, err = swarmClient.Download(feedManifestAddressHex, "")
   481  	if err != nil {
   482  		t.Fatal(err)
   483  	}
   484  	gotData, err = ioutil.ReadAll(f)
   485  	if err != nil {
   486  		t.Fatal(err)
   487  	}
   488  
   489  	// Check that we get back the original data:
   490  	if !bytes.Equal(dataBytes, gotData) {
   491  		t.Fatalf("Expected: %v, got %v", manifestAddress, gotData)
   492  	}
   493  }
   494  
   495  // TestClientCreateUpdateFeed will check that feeds can be created and updated via the HTTP client.
   496  func TestClientCreateUpdateFeed(t *testing.T) {
   497  
   498  	signer, _ := newTestSigner()
   499  
   500  	srv := swarmhttp.NewTestSwarmServer(t, serverFunc, nil)
   501  	client := NewClient(srv.URL)
   502  	defer srv.Close()
   503  
   504  	// set raw data for the feed update
   505  	databytes := []byte("En un lugar de La Mancha, de cuyo nombre no quiero acordarme...")
   506  
   507  	// our feed topic name
   508  	topic, _ := feed.NewTopic("El Quijote", nil)
   509  	createRequest := feed.NewFirstRequest(topic)
   510  
   511  	createRequest.SetData(databytes)
   512  	if err := createRequest.Sign(signer); err != nil {
   513  		t.Fatalf("Error signing update: %s", err)
   514  	}
   515  
   516  	feedManifestHash, err := client.CreateFeedWithManifest(createRequest)
   517  	if err != nil {
   518  		t.Fatal(err)
   519  	}
   520  
   521  	correctManifestAddrHex := "0e9b645ebc3da167b1d56399adc3276f7a08229301b72a03336be0e7d4b71882"
   522  	if feedManifestHash != correctManifestAddrHex {
   523  		t.Fatalf("Response feed manifest mismatch, expected '%s', got '%s'", correctManifestAddrHex, feedManifestHash)
   524  	}
   525  
   526  	reader, err := client.QueryFeed(nil, correctManifestAddrHex)
   527  	if err != nil {
   528  		t.Fatalf("Error retrieving feed updates: %s", err)
   529  	}
   530  	defer reader.Close()
   531  	gotData, err := ioutil.ReadAll(reader)
   532  	if err != nil {
   533  		t.Fatal(err)
   534  	}
   535  	if !bytes.Equal(databytes, gotData) {
   536  		t.Fatalf("Expected: %v, got %v", databytes, gotData)
   537  	}
   538  
   539  	// define different data
   540  	databytes = []byte("... no ha mucho tiempo que vivĂ­a un hidalgo de los de lanza en astillero ...")
   541  
   542  	updateRequest, err := client.GetFeedRequest(nil, correctManifestAddrHex)
   543  	if err != nil {
   544  		t.Fatalf("Error retrieving update request template: %s", err)
   545  	}
   546  
   547  	updateRequest.SetData(databytes)
   548  	if err := updateRequest.Sign(signer); err != nil {
   549  		t.Fatalf("Error signing update: %s", err)
   550  	}
   551  
   552  	if err = client.UpdateFeed(updateRequest); err != nil {
   553  		t.Fatalf("Error updating feed: %s", err)
   554  	}
   555  
   556  	reader, err = client.QueryFeed(nil, correctManifestAddrHex)
   557  	if err != nil {
   558  		t.Fatalf("Error retrieving feed updates: %s", err)
   559  	}
   560  	defer reader.Close()
   561  	gotData, err = ioutil.ReadAll(reader)
   562  	if err != nil {
   563  		t.Fatal(err)
   564  	}
   565  	if !bytes.Equal(databytes, gotData) {
   566  		t.Fatalf("Expected: %v, got %v", databytes, gotData)
   567  	}
   568  
   569  	// now try retrieving feed updates without a manifest
   570  
   571  	fd := &feed.Feed{
   572  		Topic: topic,
   573  		User:  signer.Address(),
   574  	}
   575  
   576  	lookupParams := feed.NewQueryLatest(fd, lookup.NoClue)
   577  	reader, err = client.QueryFeed(lookupParams, "")
   578  	if err != nil {
   579  		t.Fatalf("Error retrieving feed updates: %s", err)
   580  	}
   581  	defer reader.Close()
   582  	gotData, err = ioutil.ReadAll(reader)
   583  	if err != nil {
   584  		t.Fatal(err)
   585  	}
   586  	if !bytes.Equal(databytes, gotData) {
   587  		t.Fatalf("Expected: %v, got %v", databytes, gotData)
   588  	}
   589  }