Some code style fixes

Author: ldusan84

lib/internal/Magento/Framework/App/Feed.php

@@ -24,6 +24,8 @@ public function __construct(
 
     /**
      * Returns the formatted feed content
+     *
+     * @param string $format
      * 
      * @return string
      */

lib/internal/Magento/Framework/App/FeedFactory.php

@@ -45,12 +45,7 @@ public function __construct(
     }
 
     /**
-     * Get a new \Magento\Framework\App\FeedInterface object from a custom array
-     *
-     * @throws \Magento\Framework\Exception\InputException
-     * @param  array  $data
-     * @param  string $format
-     * @return \Magento\Framework\App\FeedInterface
+     * {@inheritdoc}
      */
     public function create(
         array $data, 
@@ -63,7 +58,7 @@ public function create(
             );
         }
 
-        if (!is_subclass_of($this->formats[$format], '\Magento\Framework\App\FeedInterface')) {
+        if (!is_subclass_of($this->formats[$format], \Magento\Framework\App\FeedInterface::class)) {
             throw new \Magento\Framework\Exception\InputException(
                 __('Wrong format handler type'),
                 $e

lib/internal/Magento/Framework/App/FeedFactoryInterface.php

@@ -5,15 +5,21 @@
  */
 namespace Magento\Framework\App;
 
+/**
+ * Feed factory interface
+ */
 interface FeedFactoryInterface
 {
-
+    /**
+     * RSS feed input format
+     */
     const FORMAT_RSS = 'rss';
 
     /**
      * Returns FeedInterface object from a custom array
      * 
      * @throws \Magento\Framework\Exception\InputException
+     * @throws \Magento\Framework\Exception\RuntimeException
      * @param  array  $data
      * @param  string $format
      * @return FeedInterface

lib/internal/Magento/Framework/App/FeedInterface.php

@@ -5,11 +5,19 @@
  */
 namespace Magento\Framework\App;
 
+/**
+ * Feed interface
+ */
 interface FeedInterface
 {
+	/**
+     * XML feed output format
+     */
     const FORMAT_XML = 'xml';
 
     /**
+     * @param string $format
+     * 
      * @return string
      */
     public function getFormattedContentAs(