Reland 'Traffic annotation auditor and unittest updated.'

The following changes were done:
 1- Auditor adds a list of OSes that actively use each annotation to
    annotations.xml, so that removing annotation from one OS and keeping
    it in another would not result in marking it deprecated.
 2- A script is added to tools/traffic_anntotation/scripts, to call all
    scripts that update a give file when annotations.xml is modified, or
    to run unittests that ensure these files are up to date.
 3- 'test-only' switch added to Auditor. When this switch is present,
    auditor only checks if annotations.xml is up to date and issues an
    error it if is not. When switch is not specified, annotations.xml
    may get updated and if so, the above mentioned script is called to
    update downstream files.
 4- Auditor will prevent use of deprecated unique ids.
 5- Unittest checks that annotations.xml is loadable and its content are
    valid.
 6- Unittest calls the script mentioned in (2) to test if downstream
    files are correctly updated.

Bug: 656607
Bug: 690323
Change-Id: I00acbddbe14eeee23317bb9990069e00558a5bb4
Reviewed-on: https://chromium-review.googlesource.com/645088
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Reviewed-by: Martin Šrámek <msramek@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#501206}
Reviewed-on: https://chromium-review.googlesource.com/663724
Cr-Commit-Position: refs/heads/master@{#501584}

tools/metrics/histograms/enums.xml

@@ -38791,6 +38791,7 @@ Called by update_traffic_annotation_histograms.py.-->
   <int value="8561691" label="safe_browsing_v4_get_hash"/>
   <int value="9459438" label="external_policy_fetcher"/>
   <int value="13211343" label="suggestions_image_manager"/>
+  <int value="13694792" label="desktop_ios_promotion"/>
   <int value="14257952" label="supervised_user_url_filter"/>
   <int value="15418154" label="ntp_snippets_fetch"/>
   <int value="16469669" label="background_fetch_context"/>
@@ -38854,6 +38855,7 @@ Called by update_traffic_annotation_histograms.py.-->
   <int value="56275203" label="save_file_manager"/>
   <int value="56351037" label="download_web_contents_frame"/>
   <int value="56434025" label="gcm_subscription"/>
+  <int value="56866367" label="pdf_plugin_placeholder"/>
   <int value="57144960" label="sync_http_bridge"/>
   <int value="57276415" label="chrome_expect_ct_reporter"/>
   <int value="58963098" label="resource_dispather_host"/>
@@ -38874,6 +38876,7 @@ Called by update_traffic_annotation_histograms.py.-->
   <int value="68561428" label="data_reduction_proxy_pingback"/>
   <int value="68745894" label="safe_browsing_get_full_hash"/>
   <int value="70126372" label="notification_image_reporter"/>
+  <int value="70796791" label="content_resource_fetcher"/>
   <int value="71251498" label="privet_http_impl"/>
   <int value="71578042" label="cloud_print_backend"/>
   <int value="72354423" label="invalidation_service"/>
@@ -38900,6 +38903,7 @@ Called by update_traffic_annotation_histograms.py.-->
   <int value="88863520" label="autofill_query"/>
   <int value="89771989" label="asset_links"/>
   <int value="91597383" label="gaia_auth_login"/>
+  <int value="93232258" label="mojo_context_state"/>
   <int value="95588446" label="payments_sync_cards"/>
   <int value="95682324" label="ranker_url_fetcher"/>
   <int value="95711309" label="ntp_contextual_suggestions_fetch"/>
@@ -38908,6 +38912,7 @@ Called by update_traffic_annotation_histograms.py.-->
   <int value="97199008" label="doodle_fetcher"/>
   <int value="97978464" label="gaia_auth_fetch_for_uber"/>
   <int value="98123737" label="devtools_interceptor"/>
+  <int value="99279418" label="rlz_ping"/>
   <int value="100545943" label="webui_content_scripts_download"/>
   <int value="101725581" label="cros_recovery_image_download"/>
   <int value="101845102" label="blink_resource_loader"/>

tools/traffic_annotation/auditor/auditor_result.cc

@@ -86,6 +86,13 @@ std::string AuditorResult::ToText() const {
           "word and should be changed.",
           details_[0].c_str(), file_path_.c_str(), line_);
 
+    case AuditorResult::Type::ERROR_DEPRECATED_UNIQUE_ID_HASH_CODE:
+      DCHECK(details_.size());
+      return base::StringPrintf(
+          "Unique id '%s' in '%s:%i' has a hash code similar to a deprecated "
+          "unique id and should be changed.",
+          details_[0].c_str(), file_path_.c_str(), line_);
+
     case AuditorResult::Type::ERROR_DUPLICATE_UNIQUE_ID_HASH_CODE:
       DCHECK_EQ(details_.size(), 2u);
       return base::StringPrintf(

tools/traffic_annotation/auditor/auditor_result.h

@@ -18,13 +18,15 @@ class AuditorResult {
                              // MISSING_TRAFFIC_ANNOTATION tag.
     ERROR_NO_ANNOTATION,     // A function is called with NO_ANNOTATION tag.
     ERROR_SYNTAX,            // Annotation syntax is not right.
-    ERROR_RESERVED_UNIQUE_ID_HASH_CODE,   // A unique id has a hash code similar
-                                          // to a reserved word.
-    ERROR_DUPLICATE_UNIQUE_ID_HASH_CODE,  // Two unique ids have similar hash
-                                          // codes.
-    ERROR_UNIQUE_ID_INVALID_CHARACTER,    // A unique id contanins a characer
-                                          // which is not alphanumeric or
-                                          // underline.
+    ERROR_RESERVED_UNIQUE_ID_HASH_CODE,  // A unique id has a hash code similar
+                                         // to a reserved word.
+    ERROR_DEPRECATED_UNIQUE_ID_HASH_CODE,  // A unique id has a hash code
+                                           // equal to a deprecated one.
+    ERROR_DUPLICATE_UNIQUE_ID_HASH_CODE,   // Two unique ids have equal hash
+                                           // codes.
+    ERROR_UNIQUE_ID_INVALID_CHARACTER,     // A unique id contanins a characer
+                                           // which is not alphanumeric or
+                                           // underline.
     ERROR_MISSING_ANNOTATION,     // A function that requires annotation is not
                                   // annotated.
     ERROR_MISSING_EXTRA_ID,       // Annotation does not have a valid extra id.

tools/traffic_annotation/auditor/traffic_annotation_auditor.cc

@@ -14,6 +14,7 @@
 #include "build/build_config.h"
 #include "net/traffic_annotation/network_traffic_annotation.h"
 #include "net/traffic_annotation/network_traffic_annotation_test_helper.h"
+#include "tools/traffic_annotation/auditor/traffic_annotation_exporter.h"
 #include "tools/traffic_annotation/auditor/traffic_annotation_file_filter.h"
 
 namespace {
@@ -135,10 +136,8 @@ bool TrafficAnnotationAuditor::RunClangTool(
   }
   base::CloseFile(options_file);
 
-  base::CommandLine cmdline(source_path_.Append(FILE_PATH_LITERAL("tools"))
-                                .Append(FILE_PATH_LITERAL("clang"))
-                                .Append(FILE_PATH_LITERAL("scripts"))
-                                .Append(FILE_PATH_LITERAL("run_tool.py")));
+  base::CommandLine cmdline(source_path_.Append(
+      FILE_PATH_LITERAL("tools/clang/scripts/run_tool.py")));
 
 #if defined(OS_WIN)
   cmdline.PrependWrapper(L"python");
@@ -325,11 +324,18 @@ void TrafficAnnotationAuditor::PurgeAnnotations(
       extracted_annotations_.end());
 }
 
-void TrafficAnnotationAuditor::CheckDuplicateHashes() {
+bool TrafficAnnotationAuditor::CheckDuplicateHashes() {
   const std::map<int, std::string> reserved_ids = GetReservedUniqueIDs();
 
   std::map<int, std::vector<AnnotationID>> collisions;
   std::set<int> to_be_purged;
+  std::set<int> deprecated_ids;
+
+  // Load deprecated Hashcodes.
+  if (!TrafficAnnotationExporter(source_path_)
+           .GetDeprecatedHashCodes(&deprecated_ids)) {
+    return false;
+  }
 
   for (AnnotationInstance& instance : extracted_annotations_) {
     // Check if partial and branched completing annotation have an extra id
@@ -382,6 +388,16 @@ void TrafficAnnotationAuditor::CheckDuplicateHashes() {
         continue;
       }
 
+      // If the id's hash code was formerly used by a deprecated annotation,
+      // add an error.
+      if (base::ContainsKey(deprecated_ids, current.hash)) {
+        errors_.push_back(AuditorResult(
+            AuditorResult::Type::ERROR_DEPRECATED_UNIQUE_ID_HASH_CODE,
+            current.text, instance.proto.source().file(),
+            instance.proto.source().line()));
+        continue;
+      }
+
       // Check for collisions.
       if (!base::ContainsKey(collisions, current.hash)) {
         collisions[current.hash] = std::vector<AnnotationID>();
@@ -425,6 +441,7 @@ void TrafficAnnotationAuditor::CheckDuplicateHashes() {
   }
 
   PurgeAnnotations(to_be_purged);
+  return true;
 }
 
 void TrafficAnnotationAuditor::CheckUniqueIDsFormat() {
@@ -608,10 +625,12 @@ void TrafficAnnotationAuditor::CheckAnnotationsContents() {
                                   new_annotations.end());
 }
 
-void TrafficAnnotationAuditor::RunAllChecks() {
-  CheckDuplicateHashes();
+bool TrafficAnnotationAuditor::RunAllChecks() {
+  if (!CheckDuplicateHashes())
+    return false;
   CheckUniqueIDsFormat();
   CheckAnnotationsContents();
 
   CheckAllRequiredFunctionsAreAnnotated();
+  return true;
 }
\ No newline at end of file

tools/traffic_annotation/auditor/traffic_annotation_auditor.h

@@ -66,9 +66,10 @@ class TrafficAnnotationAuditor {
                     AuditorException::ExceptionType exception_type);
 
   // Checks to see if any unique id or extra id or their hash code are
-  // duplicated. Adds errors to |errors_| and purges annotations with duplicate
-  // ids.
-  void CheckDuplicateHashes();
+  // duplicated, either in currently existing annotations, or in deprecated
+  // ones. Adds errors to |errors_| and purges annotations with duplicate ids.
+  // Returns false if any errors happen while checking.
+  bool CheckDuplicateHashes();
 
   // Checks to see if unique ids only include alphanumeric characters and
   // underline. Adds errors to |errors_| and purges annotations with
@@ -89,7 +90,7 @@ class TrafficAnnotationAuditor {
   bool CheckIfCallCanBeUnannotated(const CallInstance& call);
 
   // Performs all checks on extracted annotations and calls.
-  void RunAllChecks();
+  bool RunAllChecks();
 
   // Returns a mapping of reserved unique ids' hash codes to the unique ids'
   // texts. This list includes all unique ids that are defined in

tools/traffic_annotation/auditor/traffic_annotation_auditor_ui.cc

@@ -19,7 +19,7 @@ namespace {
 const char* HELP_TEXT = R"(
 Traffic Annotation Auditor
 Extracts network traffic annotaions from the repository, audits them for errors
-and coverage, and produces reports.
+and coverage, produces reports, and updates related files.
 
 Usage: traffic_annotation_auditor [OPTION]... [path_filters]
 
@@ -40,6 +40,12 @@ Options:
   --full-run          Optional flag asking the tool to run on the whole
                       repository without text filtering files. Using this flag
                       may increase processing time x40.
+  --test-only         Optional flag to request just running tests and not
+                      updating any file. If not specified,
+                      'tools/traffic_annotation/summary/annotations.xml' might
+                      get updated and if it does, 'tools/traffic_annotation/
+                      scripts/annotations_xml_downstream_updater.py will
+                      be called to update downstream files.
   --summary-file      Optional path to the output file with all annotations.
   --annotations-file  Optional path to a TSV output file with all annotations.
   path_filters        Optional paths to filter what files the tool is run on.
@@ -48,11 +54,32 @@ Example:
   traffic_annotation_auditor --build-dir=out/Debug summary-file=report.txt
 )";
 
-const base::FilePath kAnnotationsXmlPath(
-    FILE_PATH_LITERAL("tools/traffic_annotation/summary/annotations.xml"));
-
+const base::FilePath kDownstreamUpdater(FILE_PATH_LITERAL(
+    "tools/traffic_annotation/scripts/annotations_xml_downstream_caller.py"));
 }  // namespace
 
+// Calls |kDownstreamUpdater| script to update files that depend on
+// annotations.xml.
+bool RunAnnotationDownstreamUpdater(const base::FilePath& source_path) {
+  base::CommandLine cmdline(source_path.Append(kDownstreamUpdater));
+  int exit_code;
+
+#if defined(OS_WIN)
+  cmdline.PrependWrapper(L"python");
+  exit_code =
+      system(base::UTF16ToASCII(cmdline.GetCommandLineString()).c_str());
+#else
+  exit_code = system(cmdline.GetCommandLineString().c_str());
+#endif
+
+  if (exit_code) {
+    LOG(ERROR) << "Running " << kDownstreamUpdater.MaybeAsASCII()
+               << " failed with exit code: " << exit_code;
+    return false;
+  }
+  return true;
+}
+
 // Writes a summary of annotations, calls, and errors.
 bool WriteSummaryFile(const base::FilePath& filepath,
                       const std::vector<AnnotationInstance>& annotations,
@@ -262,6 +289,7 @@ int main(int argc, char* argv[]) {
   base::FilePath extractor_input =
       command_line.GetSwitchValuePath("extractor-input");
   bool full_run = command_line.HasSwitch("full-run");
+  bool test_only = command_line.HasSwitch("test-only");
   base::FilePath summary_file = command_line.GetSwitchValuePath("summary-file");
   base::FilePath annotations_file =
       command_line.GetSwitchValuePath("annotations-file");
@@ -321,7 +349,10 @@ int main(int argc, char* argv[]) {
     return 1;
 
   // Perform checks.
-  auditor.RunAllChecks();
+  if (!auditor.RunAllChecks()) {
+    LOG(ERROR) << "Running checks failed.";
+    return 1;
+  }
 
   // Write the summary file.
   if (!summary_file.empty() &&
@@ -331,15 +362,6 @@ int main(int argc, char* argv[]) {
     return 1;
   }
 
-  // Update annotations list.
-  if (!TrafficAnnotationExporter().UpdateAnnotationsXML(
-          source_path.Append(kAnnotationsXmlPath),
-          auditor.extracted_annotations(),
-          TrafficAnnotationAuditor::GetReservedUniqueIDs())) {
-    LOG(ERROR) << "Could not update annotations XML.";
-    return 1;
-  }
-
   // Write annotations TSV file.
   if (!annotations_file.empty() &&
       !WriteAnnotationsFile(annotations_file,
@@ -348,6 +370,23 @@ int main(int argc, char* argv[]) {
     return 1;
   }
 
+  // Test/Update annotations.xml.
+  TrafficAnnotationExporter exporter(source_path);
+  if (!exporter.UpdateAnnotations(
+          auditor.extracted_annotations(),
+          TrafficAnnotationAuditor::GetReservedUniqueIDs())) {
+    return 1;
+  }
+  if (exporter.modified()) {
+    if (test_only) {
+      printf("Error: annotation.xml needs update.\n");
+    } else if (!exporter.SaveAnnotationsXML() ||
+               !RunAnnotationDownstreamUpdater(source_path)) {
+      LOG(ERROR) << "Could not update annotations XML or downstream files.";
+      return 1;
+    }
+  }
+
   // Dump Errors and Warnings to stdout.
   const std::vector<AuditorResult>& errors = auditor.errors();
   for (const auto& error : errors) {

tools/traffic_annotation/auditor/traffic_annotation_auditor_unittest.cc

@@ -11,9 +11,12 @@
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
 #include "net/traffic_annotation/network_traffic_annotation.h"
 #include "net/traffic_annotation/network_traffic_annotation_test_helper.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "tools/traffic_annotation/auditor/traffic_annotation_exporter.h"
 #include "tools/traffic_annotation/auditor/traffic_annotation_file_filter.h"
 
 namespace {
@@ -31,7 +34,12 @@ const char* kIrrelevantFiles[] = {
 const char* kRelevantFiles[] = {
     "tools/traffic_annotation/auditor/tests/relevant_file_name_and_content.cc",
     "tools/traffic_annotation/auditor/tests/relevant_file_name_and_content.mm"};
-}
+
+const base::FilePath kDownstreamUnittests(
+    FILE_PATH_LITERAL("tools/traffic_annotation/scripts/"
+                      "annotations_xml_downstream_caller.py"));
+
+}  // namespace
 
 using namespace testing;
 
@@ -818,4 +826,28 @@ TEST_F(TrafficAnnotationAuditorTest, CreateCompleteAnnotation) {
           NetworkTrafficAnnotation_TrafficSemantics_Destination_LOCAL);
   EXPECT_NE(instance.CreateCompleteAnnotation(other, &combination).type(),
             AuditorResult::Type::RESULT_OK);
+}
+
+// Tests if Annotations.xml has proper content.
+TEST_F(TrafficAnnotationAuditorTest, AnnotationsXML) {
+  TrafficAnnotationExporter exporter(source_path());
+
+  EXPECT_TRUE(exporter.LoadAnnotationsXML());
+  EXPECT_TRUE(exporter.CheckReportItems());
+}
+
+// Tests if downstream files depending on of Annotations.xml are updated.
+TEST_F(TrafficAnnotationAuditorTest, AnnotationsDownstreamUnittests) {
+  base::CommandLine cmdline(source_path().Append(kDownstreamUnittests));
+  cmdline.AppendSwitch("test");
+
+  int tests_result;
+#if defined(OS_WIN)
+  cmdline.PrependWrapper(L"python");
+  tests_result =
+      system(base::UTF16ToASCII(cmdline.GetCommandLineString()).c_str());
+#else
+  tests_result = system(cmdline.GetCommandLineString().c_str());
+#endif
+  EXPECT_EQ(0, tests_result);
 }
\ No newline at end of file

tools/traffic_annotation/auditor/traffic_annotation_exporter.h

@@ -6,48 +6,54 @@
 #define TOOLS_TRAFFIC_ANNOTATION_AUDITOR_TRAFFIC_ANNOTATION_EXPORTER_H_
 
 #include <map>
+#include <set>
 #include <vector>
 
 #include "base/files/file_path.h"
-#include "base/strings/string_util.h"
 #include "tools/traffic_annotation/auditor/instance.h"
 
 class TrafficAnnotationExporter {
  public:
-  TrafficAnnotationExporter() = default;
-  ~TrafficAnnotationExporter() = default;
+  TrafficAnnotationExporter(const base::FilePath& source_path);
+  ~TrafficAnnotationExporter();
   TrafficAnnotationExporter(const TrafficAnnotationExporter&) = delete;
   TrafficAnnotationExporter(TrafficAnnotationExporter&&) = delete;
 
-  // Updates the xml file including annotations unique id, hash code, content
-  // hash code, and a flag specifying that annotation is depricated.
-  bool UpdateAnnotationsXML(const base::FilePath& filepath,
-                            const std::vector<AnnotationInstance>& annotations,
-                            const std::map<int, std::string>& reserved_ids);
+  // Loads annotations from annotations.xml file into |report_items_|.
+  bool LoadAnnotationsXML();
+
+  // Updates |report_items_| with current set of extracted annotations and
+  // reserved ids. Sets the |modified_| flag if any item is updated.
+  bool UpdateAnnotations(const std::vector<AnnotationInstance>& annotations,
+                         const std::map<int, std::string>& reserved_ids);
+
+  // Saves |report_items_| into annotations.xml.
+  bool SaveAnnotationsXML();
+
+  // Produces the list of deprecated hash codes. Returns false if
+  // annotations.xml is not and cannot be loaded.
+  bool GetDeprecatedHashCodes(std::set<int>* hash_codes);
+
+  bool modified() { return modified_; }
+
+  // Runs tests on content of |report_items_|.
+  bool CheckReportItems();
 
  private:
   struct ReportItem {
-    ReportItem(std::string id, int hash_code, int content_hash)
-        : unique_id(id),
-          unique_id_hash_code(hash_code),
-          deprecation_date(std::string()),
-          content_hash_code(content_hash) {}
-    ReportItem(std::string id, int hash_code) : ReportItem(id, hash_code, -1) {}
-    ReportItem() : ReportItem(std::string(), -1, -1) {}
-
-    static bool Compare(const ReportItem& a, const ReportItem& b) {
-      return base::CompareCaseInsensitiveASCII(a.unique_id, b.unique_id) < 0;
-    }
-
-    std::string unique_id;
+    ReportItem();
+    ReportItem(const ReportItem& other);
+    ~ReportItem();
+
     int unique_id_hash_code;
     std::string deprecation_date;
     int content_hash_code;
+    std::vector<std::string> os_list;
   };
 
-  // Loads annotations from the given XML file.
-  bool LoadAnnotationsFromXML(const base::FilePath& filepath,
-                              std::vector<ReportItem>* items);
+  std::map<std::string, ReportItem> report_items_;
+  const base::FilePath source_path_;
+  bool modified_;
 };
 
 #endif  // TOOLS_TRAFFIC_ANNOTATION_AUDITOR_TRAFFIC_ANNOTATION_EXPORTER_H_
\ No newline at end of file

tools/traffic_annotation/scripts/README.md

+# Traffic Annotation Scripts
+This file describes the scripts in `tools/traffic_annotation/scripts`
+
+# annotations_xml_downstream_caller.py
+This script calls all scripts that either update a file based on
+`annotations.xml`, or test if a file is in sync with it. Call with `test` switch
+for test mode.

tools/traffic_annotation/scripts/annotations_xml_downstream_caller.py

+#!/usr/bin/env python
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+""" Runs all scripts that use
+      'tools/traffic_annotation/summary/annotations.xml' to update a file, or
+      test if a file is in sync with it. Use with 'test' switch for test mode.
+      Add your scripts to PROD_SCRIPTS or TEST_SCRIPTS.
+"""
+
+import os.path
+import subprocess
+import sys
+
+# Add your update scripts here. Each list item will have the script name and the
+# list of arguments.
+PROD_SCRIPTS = [
+  ["tools/metrics/histograms/update_traffic_annotation_histograms.py", []]]
+
+# Add your test scripts here. Each list item will have the script name and the
+# list of arguments.
+TEST_SCRIPTS = []
+
+
+def main(test_mode):
+  src_path = os.path.abspath(
+      os.path.join(os.path.dirname(__file__), "..", "..", ".."))
+
+  for script in TEST_SCRIPTS if test_mode else PROD_SCRIPTS:
+    args = [os.path.join(src_path, script[0])]
+    args += script[1]
+    if sys.platform == "win32":
+      args.insert(0, "python")
+
+    result = subprocess.call(args)
+    if result:
+      if test_mode:
+        logging.error("Running '%s' script failed with error code: %i." % (
+                      script, result))
+      return result
+  return 0
+
+
+if __name__ == "__main__":
+  test_mode = (len(sys.argv) > 1 and "test" in sys.argv[1])
+  sys.exit(main(test_mode))

tools/traffic_annotation/summary/README.md

@@ -5,16 +5,16 @@ This file describes the `tools/traffic_annotation/summary/annotations.xml`.
 `annotations.xml` includes the summary of all network traffic annotations in
 Chromium repository. The content includes complete annotations and the merged
 partial and completing (and branched completing) annotations.
-For each annotation, unique id, hash code of unique id, and hash code of content
-is presented. If annotation is a reserved one, instead of content hash code, a
-`reserved` attribute is included.
+For each annotation, unique id, hash code of unique id, hash code of the
+content, and the list of OSes using this annotation is presented. If annotation
+is a reserved one, instead of content hash code, a `reserved` attribute is
+included.
 Once an annotation is removed from the repository, a `deprecated` attribute is
 added to its item in this file, with value equal to the deprecation date.
 These items can be manually or automatically pruned after sufficient time.
 
 # How to Generate/Update.
 Run `traffic_annotation_auditor` to check for annotations correctness and
-automatic update.
-After each change in `annotations.xml`, please call
-`tools/metrics/histograms/update_traffic_annotation_histograms.py` to update
-annotation enums used in histograms.
+automatic update. After each modification of`annotations.xml`, auditor calls
+`tools/traffic_annotation/scripts/annotations_xml_downstream_updater.py` to
+update all users of this file.
\ No newline at end of file