diff --git a/.travis.yml b/.travis.yml
index ef28219..41a6d8b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,7 +11,6 @@ addons:
     - expect
 
 php:
-- '7.0'
 - '7.1'
 - '7.2'
 - '7.3'
diff --git a/README.md b/README.md
index 5d04e81..11ae41a 100644
--- a/README.md
+++ b/README.md
@@ -116,16 +116,18 @@ var_dump($response);
 $response = $client->wri($query);
 var_dump($response);
 
-// Export every row using foreach.
-foreach ($response as $row){
-  var_export($row);
+// The following for loop allows you to skip elements for which
+// $iterator->current() throws an exception, rather than breaking
+// the loop.
+for ($response->rewind(); $response->valid(); $response->next()) {
+    try {
+        $value = $response->current();
+    } catch (Exception $exception) {
+        continue;
+    }
+
+    # ...
 }
-
-// Work with resource as with ordinary array
-end($response);
-key($response);
-current($response);
-stat($response);
 ```
 
 ### How to configure the client
diff --git a/src/Client.php b/src/Client.php
index b230a2e..d65077b 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -6,7 +6,6 @@ use RouterOS\Exceptions\ClientException;
 use RouterOS\Exceptions\ConfigException;
 use RouterOS\Exceptions\QueryException;
 use RouterOS\Helpers\ArrayHelper;
-use RouterOS\Interfaces\ClientInterface;
 
 /**
  * Class Client for RouterOS management
diff --git a/src/ResponseIterator.php b/src/ResponseIterator.php
index 8f8e4cc..6ff9028 100644
--- a/src/ResponseIterator.php
+++ b/src/ResponseIterator.php
@@ -2,6 +2,11 @@
 
 namespace RouterOS;
 
+use \Iterator,
+    \ArrayAccess,
+    \Countable,
+    \Serializable;
+
 /**
  * This class was created by memory save reasons, it convert response
  * from RouterOS to readable array in safe way.
@@ -15,7 +20,7 @@ namespace RouterOS;
  * @link    https://github.com/arily/RouterOSResponseArray
  * @since   1.0.0
  */
-class ResponseIterator implements \Iterator, \ArrayAccess, \Countable
+class ResponseIterator implements Iterator, ArrayAccess, Countable, Serializable
 {
     /**
      * List of parser results from array
@@ -36,7 +41,7 @@ class ResponseIterator implements \Iterator, \ArrayAccess, \Countable
      *
      * @var int
      */
-    private $current;
+    private $current = 0;
 
     /**
      * Object of main client
@@ -95,6 +100,14 @@ class ResponseIterator implements \Iterator, \ArrayAccess, \Countable
     }
 
     /**
+     * Previous value
+     */
+    public function prev()
+    {
+        --$this->current;
+    }
+
+    /**
      * Return the current element
      *
      * @return mixed
@@ -105,8 +118,14 @@ class ResponseIterator implements \Iterator, \ArrayAccess, \Countable
             return $this->parsed[$this->current];
         }
 
-        if (isset($this->raw[$this->current])) {
-            return $this->client->parseResponse($this->raw[$this->current])[0];
+        if ($this->valid()) {
+
+            if (!isset($this->parsed[$this->current])) {
+                $value = $this->client->parseResponse($this->raw[$this->current])[0];
+                $this->offsetSet($this->current, $value);
+            }
+
+            return $this->parsed[$this->current];
         }
 
         return null;
@@ -207,4 +226,24 @@ class ResponseIterator implements \Iterator, \ArrayAccess, \Countable
 
         return false;
     }
+
+    /**
+     * String representation of object
+     *
+     * @return string
+     */
+    public function serialize(): string
+    {
+        return serialize($this->raw);
+    }
+
+    /**
+     * Constructs the object
+     *
+     * @param string $serialized
+     */
+    public function unserialize($serialized)
+    {
+        $this->raw = unserialize($serialized, null);
+    }
 }
diff --git a/tests/ClientTest.php b/tests/ClientTest.php
index f6551c3..0895f8b 100644
--- a/tests/ClientTest.php
+++ b/tests/ClientTest.php
@@ -12,21 +12,21 @@ use RouterOS\Exceptions\ClientException;
 
 class ClientTest extends TestCase
 {
-    public function test__construct()
+    public function test__construct(): void
     {
         try {
             $config = new Config();
             $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))->set('host', getenv('ROS_HOST'));
             $obj = new Client($config);
-            $this->assertInternalType('object', $obj);
+            $this->assertIsObject($obj);
             $socket = $obj->getSocket();
-            $this->assertInternalType('resource', $socket);
+            $this->assertIsResource($socket);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
     }
 
-    public function test__construct2()
+    public function test__construct2(): void
     {
         try {
             $config = new Config([
@@ -35,15 +35,15 @@ class ClientTest extends TestCase
                 'host' => getenv('ROS_HOST')
             ]);
             $obj    = new Client($config);
-            $this->assertInternalType('object', $obj);
+            $this->assertIsObject($obj);
             $socket = $obj->getSocket();
-            $this->assertInternalType('resource', $socket);
+            $this->assertIsResource($socket);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
     }
 
-    public function test__construct3()
+    public function test__construct3(): void
     {
         try {
             $obj = new Client([
@@ -51,15 +51,15 @@ class ClientTest extends TestCase
                 'pass' => getenv('ROS_PASS'),
                 'host' => getenv('ROS_HOST')
             ]);
-            $this->assertInternalType('object', $obj);
+            $this->assertIsObject($obj);
             $socket = $obj->getSocket();
-            $this->assertInternalType('resource', $socket);
+            $this->assertIsResource($socket);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
     }
 
-    public function test__constructEx()
+    public function test__constructEx(): void
     {
         $this->expectException(ConfigException::class);
 
@@ -69,14 +69,17 @@ class ClientTest extends TestCase
         ]);
     }
 
-    public function test__constructLegacy()
+    public function test__constructLegacy(): void
     {
         try {
-            $config = new Config();
-            $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))
-                ->set('host', getenv('ROS_HOST'))->set('port', (int) getenv('ROS_PORT_MODERN'))->set('legacy', true);
-            $obj = new Client($config);
-            $this->assertInternalType('object', $obj);
+            $obj = new Client([
+                'user'   => getenv('ROS_USER'),
+                'pass'   => getenv('ROS_PASS'),
+                'host'   => getenv('ROS_HOST'),
+                'port'   => (int) getenv('ROS_PORT_MODERN'),
+                'legacy' => true
+            ]);
+            $this->assertIsObject($obj);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
@@ -87,42 +90,52 @@ class ClientTest extends TestCase
      *
      * login() method recognise legacy router response and swap to legacy mode
      */
-    public function test__constructLegacy2()
+    public function test__constructLegacy2(): void
     {
         try {
-            $config = new Config();
-            $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))
-                ->set('host', getenv('ROS_HOST'))->set('port', (int) getenv('ROS_PORT_MODERN'))->set('legacy', false);
-            $obj = new Client($config);
-            $this->assertInternalType('object', $obj);
+            $obj = new Client([
+                'user'   => getenv('ROS_USER'),
+                'pass'   => getenv('ROS_PASS'),
+                'host'   => getenv('ROS_HOST'),
+                'port'   => (int) getenv('ROS_PORT_MODERN'),
+                'legacy' => false
+            ]);
+            $this->assertIsObject($obj);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
     }
 
 
-    public function test__constructWrongPass()
+    public function test__constructWrongPass(): void
     {
         $this->expectException(ClientException::class);
 
-        $config = (new Config())->set('attempts', 2);
-        $config->set('user', getenv('ROS_USER'))->set('pass', 'admin2')->set('host', getenv('ROS_HOST'));
-        $obj = new Client($config);
+        $obj = new Client([
+            'user'     => getenv('ROS_USER'),
+            'pass'     => 'admin2',
+            'host'     => getenv('ROS_HOST'),
+            'attempts' => 2
+        ]);
     }
 
     /**
      * @expectedException ClientException
      */
-    public function test__constructWrongNet()
+    public function test__constructWrongNet(): void
     {
         $this->expectException(ClientException::class);
 
-        $config = new Config();
-        $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))->set('host', getenv('ROS_HOST'))->set('port', 11111);
-        $obj = new Client($config);
+        $obj = new Client([
+            'user'     => getenv('ROS_USER'),
+            'pass'     => getenv('ROS_PASS'),
+            'host'     => getenv('ROS_HOST'),
+            'port'     => 11111,
+            'attempts' => 2
+        ]);
     }
 
-    public function testWriteRead()
+    public function testWriteRead(): void
     {
         $config = new Config();
         $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))->set('host', getenv('ROS_HOST'));
@@ -133,6 +146,11 @@ class ClientTest extends TestCase
         $this->assertCount(10, $readRaw);
         $this->assertEquals('=.id=*1', $readRaw[1]);
 
+        $query = new Query('/system/package/print');
+        $read  = $obj->write($query)->read();
+        $this->assertCount(13, $read);
+        $this->assertEquals('advanced-tools', $read[12]['name']);
+
         $query   = new Query('/ip/address/print');
         $readRaw = $obj->w($query)->read(false);
         $this->assertCount(10, $readRaw);
@@ -154,47 +172,68 @@ class ClientTest extends TestCase
         $this->assertEquals('!trap', $readTrap[0]);
     }
 
-    public function testWriteReadString()
+    public function testReadAsIterator(): void
     {
-        $config = new Config();
-        $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))->set('host', getenv('ROS_HOST'));
-        $obj = new Client($config);
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
+
+        $obj = $obj->write('/system/package/print')->readAsIterator();
+        $this->assertIsObject($obj);
+    }
+
+    public function testWriteReadString(): void
+    {
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
 
         $readTrap = $obj->wr('/interface', false);
         $this->assertCount(3, $readTrap);
         $this->assertEquals('!trap', $readTrap[0]);
     }
 
-    public function testWriteReadArray()
+    public function testWriteReadArray(): void
     {
-        $config = new Config();
-        $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))->set('host', getenv('ROS_HOST'));
-        $obj = new Client($config);
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
 
         $readTrap = $obj->wr(['/interface'], false);
         $this->assertCount(3, $readTrap);
         $this->assertEquals('!trap', $readTrap[0]);
     }
 
-    public function testFatal()
+    public function testFatal(): void
     {
-        $config = new Config();
-        $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))->set('host', getenv('ROS_HOST'));
-        $obj = new Client($config);
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
 
         $readTrap = $obj->wr('/quit');
         $this->assertCount(2, $readTrap);
         $this->assertEquals('!fatal', $readTrap[0]);
     }
 
-    public function testWriteEx()
+    public function testWriteEx(): void
     {
         $this->expectException(QueryException::class);
 
-        $config = new Config();
-        $config->set('user', getenv('ROS_USER'))->set('pass', getenv('ROS_PASS'))->set('host', getenv('ROS_HOST'));
-        $obj   = new Client($config);
-        $error = $obj->write($obj)->read(false);
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
+
+        $obj->write($obj)->read(false);
     }
 
 }
diff --git a/tests/ResponseIteratorTest.php b/tests/ResponseIteratorTest.php
new file mode 100644
index 0000000..9ef7b5b
--- /dev/null
+++ b/tests/ResponseIteratorTest.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace RouterOS\Tests;
+
+use PHPUnit\Framework\TestCase;
+use RouterOS\Client;
+
+class ResponseIteratorTest extends TestCase
+{
+    public function test__construct()
+    {
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
+
+        $obj = $obj->write('/system/package/print')->readAsIterator();
+        $this->assertIsObject($obj);
+    }
+
+    public function testReadWrite()
+    {
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
+
+        $readTrap = $obj->write('/system/package/print')->readAsIterator();
+        // Read from RAW
+        $this->assertCount(13, $readTrap);
+        $this->assertEquals('advanced-tools', $readTrap[12]['name']);
+        // Read from parsed
+        $this->assertCount(13, $readTrap);
+        $this->assertEquals('advanced-tools', $readTrap[12]['name']);
+
+        $readTrap = $obj->write('/ip/address/print')->readAsIterator();
+        $this->assertCount(1, $readTrap);
+        $this->assertEquals('ether1', $readTrap[0]['interface']);
+
+        $readTrap = $obj->write('/system/package/print')->readAsIterator();
+        $key      = $readTrap->key();
+        $this->assertEquals(0, $key);
+        $current = $readTrap->current();
+        $this->assertEquals('*1', $current['.id']);
+
+        $readTrap->next();
+        $key = $readTrap->key();
+        $this->assertEquals(1, $key);
+        $current = $readTrap->current();
+        $this->assertEquals('*2', $current['.id']);
+
+        $readTrap->prev();
+        $key = $readTrap->key();
+        $this->assertEquals(0, $key);
+        $current = $readTrap->current();
+        $this->assertEquals('*1', $current['.id']);
+
+        $readTrap->prev(); // Check if key is not exist
+        $key = $readTrap->key();
+        $this->assertEquals(-1, $key);
+        $current = $readTrap->current();
+        $this->assertNull($current);
+    }
+
+    public function testSerialize(): void
+    {
+        $obj = new Client([
+            'user' => getenv('ROS_USER'),
+            'pass' => getenv('ROS_PASS'),
+            'host' => getenv('ROS_HOST'),
+        ]);
+
+        $read = $obj->write('/queue/simple/print')->readAsIterator();
+        $serialize = $read->serialize();
+        $this->assertEquals('a:1:{i:0;a:1:{i:0;s:5:"!done";}}', $serialize);
+    }
+
+}