diff --git a/lib/WebDriver/AbstractWebDriver.php b/lib/WebDriver/AbstractWebDriver.php
index a0e2122..210bc00 100644
--- a/lib/WebDriver/AbstractWebDriver.php
+++ b/lib/WebDriver/AbstractWebDriver.php
@@ -154,69 +154,6 @@ protected function serializeArguments(array $arguments)
         return $arguments;
     }
 
-    /**
-     * Unserialize result (containing web elements and/or shadow roots)
-     *
-     * @param mixed $result
-     *
-     * @return mixed
-     */
-    protected function unserializeResult($result)
-    {
-        $element = is_array($result) ? $this->makeElement($result) : null;
-
-        if ($element !== null) {
-            return $element;
-        }
-
-        if (is_array($result)) {
-            foreach ($result as $key => $value) {
-                $result[$key] = $this->unserializeResult($value);
-            }
-        }
-
-        return $result;
-    }
-
-    /**
-     * Factory method for elements
-     *
-     * @param array $value
-     *
-     * @return \WebDriver\Element|\WebDriver\Shadow|null
-     */
-    protected function makeElement($value)
-    {
-        if (array_key_exists(LegacyElement::LEGACY_ELEMENT_ID, $value)) {
-            $identifier = $value[LegacyElement::LEGACY_ELEMENT_ID];
-
-            return new LegacyElement(
-                $this->getIdentifierPath('/element/' . $identifier),
-                $identifier
-            );
-        }
-
-        if (array_key_exists(Element::WEB_ELEMENT_ID, $value)) {
-            $identifier = $value[Element::WEB_ELEMENT_ID];
-
-            return new Element(
-                $this->getIdentifierPath('/element/' . $identifier),
-                $identifier
-            );
-        }
-
-        if (array_key_exists(Shadow::SHADOW_ROOT_ID, $value)) {
-            $identifier = $value[Shadow::SHADOW_ROOT_ID];
-
-            return new Shadow(
-                $this->getIdentifierPath('/shadow/' . $identifier),
-                $identifier
-            );
-        }
-
-        return null;
-    }
-
     /**
      * Curl request to webdriver server.
      *
diff --git a/lib/WebDriver/Element.php b/lib/WebDriver/Element.php
index d572834..b586d59 100644
--- a/lib/WebDriver/Element.php
+++ b/lib/WebDriver/Element.php
@@ -112,7 +112,7 @@ public function getID()
     /**
      * Get the value of an element's attribute: /session/:sessionId/element/:id/attribute/:name
      *
-     * @param string name
+     * @param string $name
      *
      * @return mixed
      */
diff --git a/lib/WebDriver/Execute.php b/lib/WebDriver/Execute.php
index 2932981..0cb9815 100644
--- a/lib/WebDriver/Execute.php
+++ b/lib/WebDriver/Execute.php
@@ -58,6 +58,69 @@ public function sync(array $jsonScript)
         return $this->unserializeResult($result['value']);
     }
 
+    /**
+     * Unserialize result (containing web elements and/or shadow roots)
+     *
+     * @param mixed $result
+     *
+     * @return mixed
+     */
+    protected function unserializeResult($result)
+    {
+        $element = is_array($result) ? $this->makeElement($result) : null;
+
+        if ($element !== null) {
+            return $element;
+        }
+
+        if (is_array($result)) {
+            foreach ($result as $key => $value) {
+                $result[$key] = $this->unserializeResult($value);
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Factory method for elements
+     *
+     * @param array $value
+     *
+     * @return \WebDriver\Element|\WebDriver\Shadow|null
+     */
+    protected function makeElement($value)
+    {
+        if (array_key_exists(LegacyElement::LEGACY_ELEMENT_ID, $value)) {
+            $identifier = $value[LegacyElement::LEGACY_ELEMENT_ID];
+
+            return new LegacyElement(
+                $this->getIdentifierPath('/element/' . $identifier),
+                $identifier
+            );
+        }
+
+        if (array_key_exists(Element::WEB_ELEMENT_ID, $value)) {
+            $identifier = $value[Element::WEB_ELEMENT_ID];
+
+            return new Element(
+                $this->getIdentifierPath('/element/' . $identifier),
+                $identifier
+            );
+        }
+
+        if (array_key_exists(Shadow::SHADOW_ROOT_ID, $value)) {
+            $identifier = $value[Shadow::SHADOW_ROOT_ID];
+
+            return new Shadow(
+                $this->getIdentifierPath('/shadow/' . $identifier),
+                $identifier
+            );
+        }
+
+        return null;
+    }
+
     /**
      * {@inheritdoc}
      */
diff --git a/lib/WebDriver/Session.php b/lib/WebDriver/Session.php
index f149b8d..39f3a95 100644
--- a/lib/WebDriver/Session.php
+++ b/lib/WebDriver/Session.php
@@ -158,7 +158,7 @@ public function open($url)
      */
     public function capabilities()
     {
-        if (! isset($this->capabilities)) {
+        if ($this->capabilities === null) {
             $result = $this->curl('GET', '');
 
             $this->capabilities = $result['value'];