diff --git a/.State b/.State
deleted file mode 100644
index a604de4..0000000
--- a/.State
+++ /dev/null
@@ -1 +0,0 @@
-finalized
diff --git a/Bench.php b/Source/Bench.php
similarity index 69%
rename from Bench.php
rename to Source/Bench.php
index 791a574..f27ec5b 100644
--- a/Bench.php
+++ b/Source/Bench.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * Hoa
  *
@@ -42,15 +44,12 @@
 /**
  * Class \Hoa\Bench.
  *
- * The \Hoa\Bench class allows to manage marks easily, and to make some
+ * The Hoa\Bench class allows to manage marks easily, and to make some
  * statistics.
- * The \Hoa\Bench class implements Iterator and Countable interfaces to iterate
+ * The Hoa\Bench class implements Iterator and Countable interfaces to iterate
  * marks, or count the number of marks.
- *
- * @copyright  Copyright © 2007-2017 Hoa community
- * @license    New BSD License
  */
-class Bench implements Iterator, \Countable
+class Bench implements Iterator\Aggregate, \Countable
 {
     /**
      * Statistic : get the result.
@@ -85,12 +84,8 @@ class Bench implements Iterator, \Countable
     /**
      * Get a mark.
      * If the mark does not exist, it will be automatically create.
-     *
-     * @param   string  $id    The mark ID.
-     * @return  \Hoa\Bench\Mark
-     * @throws  \Hoa\Bench\Exception
      */
-    public function __get($id)
+    public function __get(string $id): Mark
     {
         if (true === empty(self::$_mark)) {
             $global                         = new Mark(Mark::GLOBAL_NAME);
@@ -111,22 +106,16 @@ public function __get($id)
     /**
      * Check if a mark exists.
      * Alias of the protected markExist method.
-     *
-     * @param   string  $id    The mark ID.
-     * @return  bool
      */
-    public function __isset($id)
+    public function __isset(string $id): bool
     {
         return $this->markExists($id);
     }
 
     /**
      * Destroy a mark.
-     *
-     * @param   string  $id    The mark ID.
-     * @return  void
      */
-    public function __unset($id)
+    public function __unset(string $id)
     {
         unset(self::$_mark[$id]);
 
@@ -135,8 +124,6 @@ public function __unset($id)
 
     /**
      * Destroy all mark.
-     *
-     * @return  void
      */
     public function unsetAll()
     {
@@ -147,89 +134,26 @@ public function unsetAll()
 
     /**
      * Check if a mark already exists.
-     *
-     * @param   string     $id    The mark ID.
-     * @return  bool
      */
-    protected function markExists($id)
+    protected function markExists(string $id): bool
     {
         return isset(self::$_mark[$id]);
     }
 
     /**
-     * Get the current mark for the iterator.
-     *
-     * @return  \Hoa\Bench\Mark
-     */
-    public function current()
-    {
-        return current(self::$_mark);
-    }
-
-    /**
-     * Get the current mark ID for the iterator.
-     *
-     * @return  string
-     */
-    public function key()
-    {
-        return key(self::$_mark);
-    }
-
-    /**
-     * Advance the internal mark collection pointer, and return the current
-     * mark.
-     *
-     * @return  \Hoa\Bench\Mark
-     */
-    public function next()
-    {
-        return next(self::$_mark);
-    }
-
-    /**
-     * Rewind the internal mark collection pointer, and return the first mark.
-     *
-     * @return  \Hoa\Bench\Mark
-     */
-    public function rewind()
-    {
-        return reset(self::$_mark);
-    }
-
-    /**
-     * Check if there is a current element after calls the rewind or the next
-     * methods.
-     *
-     * @return  bool
+     * Iterate over marks.
      */
-    public function valid()
+    public function getIterator(): \Traversable
     {
-        if (empty(self::$_mark)) {
-            return false;
-        }
-
-        $key    = key(self::$_mark);
-        $return = (next(self::$_mark) ? true : false);
-        prev(self::$_mark);
-
-        if (false === $return) {
-            end(self::$_mark);
-
-            if ($key === key(self::$_mark)) {
-                $return = true;
-            }
+        foreach (self::$_mark as $mark) {
+            yield $mark;
         }
-
-        return $return;
     }
 
     /**
      * Pause all marks and return only previously started tasks.
-     *
-     * @return  array
      */
-    public function pause()
+    public function pause(): array
     {
         $startedMarks = [];
 
@@ -248,9 +172,6 @@ public function pause()
 
     /**
      * Resume a specific set of marks.
-     *
-     * @param   array  $marks    The marks to resume.
-     * @return  void
      */
     public static function resume(array $marks)
     {
@@ -266,11 +187,8 @@ public static function resume(array $marks)
      * Used in the self::getStatistic() method, no in iterator.
      * A filter is a callable that will receive 3 values about a mark: ID, time
      * result, and time pourcent. The callable must return a boolean.
-     *
-     * @param   mixed  $callable    Callable.
-     * @return  void
      */
-    public function filter($callable)
+    public function filter($callable): self
     {
         $this->_filters[] = xcallable($callable);
 
@@ -279,10 +197,8 @@ public function filter($callable)
 
     /**
      * Return all filters.
-     *
-     * @return  array
      */
-    public function getFilters()
+    public function getFilters(): array
     {
         return $this->_filters;
     }
@@ -292,12 +208,8 @@ public function getFilters()
      * Return an associative array : id => sub-array. The sub-array contains the
      * result time in second (given by the constant self::STAT_RESULT), and the
      * result pourcent (given by the constant self::START_POURCENT).
-     *
-     * @param   bool  $considerFilters    Whether we should consider filters or
-     *                                    not.
-     * @return  array
      */
-    public function getStatistic($considerFilters = true)
+    public function getStatistic(bool $considerFilters = true): array
     {
         if (empty(self::$_mark)) {
             return [];
@@ -333,10 +245,8 @@ public function getStatistic($considerFilters = true)
 
     /**
      * Get the maximum, i.e. the longest mark in time.
-     *
-     * @return  \Hoa\Bench\Mark
      */
-    public function getLongest()
+    public function getLongest(): Mark
     {
         $max     = 0;
         $outMark = null;
@@ -353,12 +263,8 @@ public function getLongest()
 
     /**
      * Draw statistic in text mode.
-     *
-     * @param   int  $width    The graphic width.
-     * @return  string
-     * @throws  \Hoa\Bench\Exception
      */
-    public function drawStatistic($width = 80)
+    public function drawStatistic(int $width = 80): string
     {
         if (empty(self::$_mark)) {
             return '';
@@ -401,20 +307,16 @@ public function drawStatistic($width = 80)
 
     /**
      * Count the number of mark.
-     *
-     * @return  int
      */
-    public function count()
+    public function count(): int
     {
         return count(self::$_mark);
     }
 
     /**
      * Alias of drawStatistic() method.
-     *
-     * @return  string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return $this->drawStatistic();
     }
@@ -423,4 +325,4 @@ public function __toString()
 /**
  * Flex entity.
  */
-Consistency::flexEntity('Hoa\Bench\Bench');
+Consistency::flexEntity(Bench::class);
diff --git a/Exception.php b/Source/Exception.php
similarity index 95%
rename from Exception.php
rename to Source/Exception.php
index f3707d8..72158ea 100644
--- a/Exception.php
+++ b/Source/Exception.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * Hoa
  *
@@ -42,9 +44,6 @@
  * Class \Hoa\Bench\Exception.
  *
  * Extending the \Hoa\Exception\Exception class.
- *
- * @copyright  Copyright © 2007-2017 Hoa community
- * @license    New BSD License
  */
 class Exception extends HoaException
 {
diff --git a/Mark.php b/Source/Mark.php
similarity index 81%
rename from Mark.php
rename to Source/Mark.php
index 0fd34c1..5f7962d 100644
--- a/Mark.php
+++ b/Source/Mark.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * Hoa
  *
@@ -41,9 +43,6 @@
  *
  * The \Hoa\Bench class contains a collection of \Hoa\Bench\Mark.
  * Each mark can be start, pause, stop, reset, or compare to an other mark.
- *
- * @copyright  Copyright © 2007-2017 Hoa community
- * @license    New BSD License
  */
 class Mark
 {
@@ -57,7 +56,7 @@ class Mark
     /**
      * Mark ID.
      *
-     * @var string
+     * @var ?string
      */
     protected $_id      = null;
 
@@ -100,10 +99,8 @@ class Mark
 
     /**
      * Built a mark (and set the ID).
-     *
-     * @param   string  $id    The mark ID.
      */
-    public function __construct($id)
+    public function __construct(?string $id)
     {
         $this->setId($id);
 
@@ -112,11 +109,8 @@ public function __construct($id)
 
     /**
      * Set the mark ID.
-     *
-     * @param   string     $id    The mark ID.
-     * @return  string
      */
-    protected function setId($id)
+    protected function setId(?string $id): ?string
     {
         $old       = $this->_id;
         $this->_id = $id;
@@ -126,10 +120,8 @@ protected function setId($id)
 
     /**
      * Get the mark ID.
-     *
-     * @return  string
      */
-    public function getId()
+    public function getId(): ?string
     {
         return $this->_id;
     }
@@ -138,11 +130,8 @@ public function getId()
      * Start the mark.
      * A mark can be started if it is in pause, stopped, or if it is the first start.
      * Else, an exception will be thrown.
-     *
-     * @return  \Hoa\Bench\Mark
-     * @throws  \Hoa\Bench\Exception
      */
-    public function start()
+    public function start(): self
     {
         if (true === $this->isStarted()) {
             if (false === $this->isPause()) {
@@ -171,13 +160,8 @@ public function start()
      * Stop the mark.
      * A mark can be stopped if it is in pause, or started. Else, an exception
      * will be thrown (or not, according to the $silent argument).
-     *
-     * @param   bool    $silent    If set to true and if the mark is not started,
-     *                             no exception will be thrown.
-     * @return  \Hoa\Bench\Mark
-     * @throws  \Hoa\Bench\Exception
      */
-    public function stop($silent = false)
+    public function stop(bool $silent = false): self
     {
         if (false === $this->isStarted()) {
             if (false === $silent) {
@@ -200,10 +184,8 @@ public function stop($silent = false)
 
     /**
      * Reset the mark.
-     *
-     * @return  \Hoa\Bench\Mark
      */
-    public function reset()
+    public function reset(): self
     {
         $this->start    = 0.0;
         $this->stop     = 0.0;
@@ -218,14 +200,8 @@ public function reset()
      * Pause the mark.
      * A mark can be in pause if it is started. Else, an exception will be
      * thrown (or not, according to the $silent argument).
-     *
-     * @param   bool    $silent    If set to true and the mark is not started,
-     *                             no exception will be throw. Idem if the mark
-     *                             is in pause.
-     * @return  \Hoa\Bench\Mark
-     * @throws  \Hoa\Bench\Exception
      */
-    public function pause($silent = false)
+    public function pause(bool $silent = false): self
     {
         if (false === $this->isStarted()) {
             if (false === $silent) {
@@ -261,10 +237,8 @@ public function pause($silent = false)
      * Get the difference between $stop and $start.
      * If the mark is still running (it contains the pause case), the current
      * microtime  will be used in stay of $stop.
-     *
-     * @return  float
      */
-    public function diff()
+    public function diff(): float
     {
         if (false === $this->isStarted() || true === $this->isPause()) {
             return $this->stop - $this->start - $this->pause;
@@ -278,11 +252,8 @@ public function diff()
      * $a op $b : return -1 if $a < $b, 0 if $a == $b, and 1 if $a > $b. We
      * compare the difference between $start and $stop, i.e. we call the diff()
      * method.
-     *
-     * @param   \Hoa\Bench\Mark  $mark    The mark to compare to.
-     * @return  int
      */
-    public function compareTo(Mark $mark)
+    public function compareTo(self $mark): int
     {
         $a = $this->diff();
         $b = $mark->diff();
@@ -300,39 +271,32 @@ public function compareTo(Mark $mark)
      * Check if the mark is running.
      *
      * @deprecated use `isStarted` instead
-     * @return  bool
      */
-    public function isRunning()
+    public function isRunning(): bool
     {
         return $this->isStarted();
     }
 
     /**
      * Check if the mark is started.
-     *
-     * @return  bool
      */
-    public function isStarted()
+    public function isStarted(): bool
     {
         return $this->_started;
     }
 
     /**
      * Check if the mark is in pause.
-     *
-     * @return  bool
      */
-    public function isPause()
+    public function isPause(): bool
     {
         return $this->_pause;
     }
 
     /**
      * Alias of the diff() method, but return a string, not a float.
-     *
-     * @return  string
      */
-    public function __toString()
+    public function __toString(): string
     {
         return (string) $this->diff();
     }
diff --git a/Test/Unit/Mark.php b/Test/Unit/Mark.php
index eedecab..65fd7da 100644
--- a/Test/Unit/Mark.php
+++ b/Test/Unit/Mark.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * Hoa
  *
@@ -43,40 +45,60 @@
  * Class \Hoa\Bench\Test\Unit\Mark.
  *
  * Test suite of the examples in the documentation.
- *
- * @copyright  Copyright © 2007-2017 Hoa community
- * @license    New BSD License
  */
 class Mark extends Test\Unit\Suite
 {
     public function case_classical()
     {
         $this
-            ->object(
-                $mark = new CUT($id = uniqid())
-            )->string($mark->getId())->isEqualTo($id)
-            ->boolean($mark->isRunning())->isFalse()
-            ->boolean($mark->isPause())->isFalse()
+            ->given($id = 'foo')
+            ->when($mark = new CUT($id))
+            ->then
+                ->string($mark->getId())
+                    ->isEqualTo($id)
+                ->boolean($mark->isRunning())
+                    ->isFalse()
+                ->boolean($mark->isPause())
+                    ->isFalse()
+
             ->assert('Start mark')
+
             ->when($SUT = $mark->start())
-                ->object($SUT)->isInstanceOf('Hoa\Bench\Mark')
-                ->boolean($mark->isRunning())->isTrue()
-                ->boolean($mark->isPause())->isFalse()
+                ->object($SUT)
+                    ->isInstanceOf(CUT::class)
+                ->boolean($mark->isRunning())
+                    ->isTrue()
+                ->boolean($mark->isPause())
+                    ->isFalse()
+
             ->assert('Pause mark')
+
             ->when($SUT = $mark->pause())
-                ->object($SUT)->isInstanceOf('Hoa\Bench\Mark')
-                ->boolean($mark->isRunning())->isTrue()
-                ->boolean($mark->isPause())->isTrue()
+                ->object($SUT)
+                    ->isInstanceOf(CUT::class)
+                ->boolean($mark->isRunning())
+                    ->isTrue()
+                ->boolean($mark->isPause())
+                    ->isTrue()
+
             ->assert('Restart mark after pause')
+
             ->when($SUT = $mark->start())
-                ->object($SUT)->isInstanceOf('Hoa\Bench\Mark')
-                ->boolean($mark->isRunning())->isTrue()
-                ->boolean($mark->isPause())->isFalse()
+                ->object($SUT)
+                    ->isInstanceOf(CUT::class)
+                ->boolean($mark->isRunning())
+                    ->isTrue()
+                ->boolean($mark->isPause())
+                    ->isFalse()
+
             ->assert('Stop mark')
+
             ->when($SUT = $mark->stop())
-                ->object($SUT)->isInstanceOf('Hoa\Bench\Mark')
-                ->boolean($mark->isRunning())->isFalse()
-                ->boolean($mark->isPause())->isFalse()
-            ;
+                ->object($SUT)
+                    ->isInstanceOf(CUT::class)
+                ->boolean($mark->isRunning())
+                    ->isFalse()
+                ->boolean($mark->isPause())
+                    ->isFalse();
     }
 }
diff --git a/composer.json b/composer.json
index d48bd79..43af3fa 100644
--- a/composer.json
+++ b/composer.json
@@ -24,16 +24,18 @@
         "source": "https://central.hoa-project.net/Resource/Library/Bench"
     },
     "require": {
-        "hoa/consistency": "~1.0",
-        "hoa/exception"  : "~1.0",
-        "hoa/iterator"   : "~2.0"
+        "php"            : ">=7.1",
+        "hoa/consistency": "dev-master",
+        "hoa/exception"  : "dev-master",
+        "hoa/iterator"   : "dev-master"
     },
     "require-dev": {
-        "hoa/test" : "~2.0"
+        "hoa/test" : "dev-master"
     },
     "autoload": {
         "psr-4": {
-            "Hoa\\Bench\\": "."
+            "Hoa\\Bench\\"      : "Source",
+            "Hoa\\Bench\\Test\\": "Test"
         }
     },
     "extra": {