Set some phpdoc to isLocalUrl

src/Composer/Repository/Vcs/VcsDriver.php

@@ -101,6 +101,11 @@ abstract class VcsDriver implements VcsDriverInterface
         return $this->remoteFilesystem->getContents($this->originUrl, $url, false);
     }
 
+    /**
+     * Return if current repository url is local
+     * 
+     * @return boolean Repository url is local
+     */
     protected static function isLocalUrl($url)
     {
         return (bool) preg_match('{^(file://|/|[a-z]:[\\\\/])}i', $url);