diff --git a/framework/yii/web/Response.php b/framework/yii/web/Response.php
index d37c66a..6801191 100644
--- a/framework/yii/web/Response.php
+++ b/framework/yii/web/Response.php
@@ -28,6 +28,21 @@ class Response extends \yii\base\Response
 	 */
 	public $ajaxRedirectCode = 278;
 
+	private $_headers;
+
+	/**
+	 * Returns the header collection.
+	 * The header collection contains the currently registered HTTP headers.
+	 * @return HeaderCollection the header collection
+	 */
+	public function getHeaders()
+	{
+		if ($this->_headers === null) {
+			$this->_headers = new HeaderCollection;
+		}
+		return $this->_headers;
+	}
+
 	/**
 	 * Sends a file to user.
 	 * @param string $fileName file name
@@ -51,7 +66,7 @@ class Response extends \yii\base\Response
 
 		if (isset($_SERVER['HTTP_RANGE'])) {
 			// client sent us a multibyte range, can not hold this one for now
-			if (strpos($_SERVER['HTTP_RANGE'],',') !== false) {
+			if (strpos($_SERVER['HTTP_RANGE'], ',') !== false) {
 				header("Content-Range: bytes $contentStart-$contentEnd/$fileSize");
 				throw new HttpException(416, 'Requested Range Not Satisfiable');
 			}
@@ -75,12 +90,12 @@ class Response extends \yii\base\Response
 			 * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
 			 */
 			// End bytes can not be larger than $end.
-			$contentEnd = ($contentEnd > $fileSize) ? $fileSize -1 : $contentEnd;
+			$contentEnd = ($contentEnd > $fileSize) ? $fileSize - 1 : $contentEnd;
 
 			// Validate the requested range and return an error if it's not correct.
 			$wrongContentStart = ($contentStart > $contentEnd || $contentStart > $fileSize - 1 || $contentStart < 0);
 
-			if ($wrongContentStart) {   
+			if ($wrongContentStart) {
 				header("Content-Range: bytes $contentStart-$contentEnd/$fileSize");
 				throw new HttpException(416, 'Requested Range Not Satisfiable');
 			}