Fix code before applying PHP CS Fixer

src/Spout/Writer/Common/Helper/ZipHelper.php

@@ -65,7 +65,7 @@ class ZipHelper
      * @param \ZipArchive $zip An opened zip archive object
      * @param string $rootFolderPath Path of the root folder that will be ignored in the archive tree.
      * @param string $localFilePath Path of the file to be added, under the root folder
-     * @param string|void $existingFileMode Controls what to do when trying to add an existing file
+     * @param string $existingFileMode Controls what to do when trying to add an existing file
      * @return void
      */
     public function addFileToArchive($zip, $rootFolderPath, $localFilePath, $existingFileMode = self::EXISTING_FILES_OVERWRITE)
@@ -90,7 +90,7 @@ class ZipHelper
      * @param \ZipArchive $zip An opened zip archive object
      * @param string $rootFolderPath Path of the root folder that will be ignored in the archive tree.
      * @param string $localFilePath Path of the file to be added, under the root folder
-     * @param string|void $existingFileMode Controls what to do when trying to add an existing file
+     * @param string $existingFileMode Controls what to do when trying to add an existing file
      * @return void
      */
     public function addUncompressedFileToArchive($zip, $rootFolderPath, $localFilePath, $existingFileMode = self::EXISTING_FILES_OVERWRITE)
@@ -143,7 +143,7 @@ class ZipHelper
     /**
      * @param \ZipArchive $zip An opened zip archive object
      * @param string $folderPath Path to the folder to be zipped
-     * @param string|void $existingFileMode Controls what to do when trying to add an existing file
+     * @param string $existingFileMode Controls what to do when trying to add an existing file
      * @return void
      */
     public function addFolderToArchive($zip, $folderPath, $existingFileMode = self::EXISTING_FILES_OVERWRITE)