docs: def compare(node1, node2):
      """Compares two Werkzeug hg versions."""
      if not os.path.isdir("a"):
          print("error: comparison feature not initialized", file=sys.stderr)
          sys.exit(4)
  
      print("=" * 80)
      print("WERKZEUG INTERNAL BENCHMARK -- COMPARE MODE".center(80))
      print("-" * 80)
  
      def _hg_update(repo, node):
          def hg(*x):
              return subprocess.call(
                  ["hg"] + list(x), cwd=repo, stdout=null_out, stderr=null_out
              )
  
          hg("revert", "-a", "--no-backup")
          client = subprocess.Popen(
              ["hg", "status", "--unknown", "-n", "-0"], stdout=subprocess.PIPE, cwd=repo
          )
          unknown = client.communicate()[0]
          if unknown:
              client = subprocess.Popen(
                  ["xargs", "-0", "rm", "-f"],
                  cwd=repo,
                  stdout=null_out,
                  stdin=subprocess.PIPE,
              )
              client.communicate(unknown)
          hg("pull", "../..")
          hg("update", node)
          if node == "tip":
              diff = subprocess.Popen(
                  ["hg", "diff"], cwd="..", stdout=subprocess.PIPE
              ).communicate()[0]
              if diff:
                  client = subprocess.Popen(
                      ["hg", "import", "--no-commit", "-"],
                      cwd=repo,
                      stdout=null_out,
                      stdin=subprocess.PIPE,
                  )
                  client.communicate(diff)
  
      _hg_update("a", node1)
      _hg_update("b", node2)
      d1 = run("a", no_header=True)
      d2 = run("b", no_header=True)
  
      print("DIRECT COMPARISON".center(80))
      print("-" * 80)
      for key in sorted(d1):
          delta = d1[key] - d2[key]
          if abs(1 - d1[key] / d2[key]) < TOLERANCE or abs(delta) < MIN_RESOLUTION:
              delta = "=="
          else:
              delta = "%+.4f (%+d%%)" % (delta, round(d2[key] / d1[key] * 100 - 100))
          print("%36s   %.4f    %.4f    %s" % (format_func(key), d1[key], d2[key], delta))
      print("-" * 80)