Easy to initialize the output zip file.

src/PhpZip/ZipFile.php

@@ -157,6 +157,13 @@ class ZipFile implements \Countable, \ArrayAccess, \Iterator, ZipConstants
         return $zipFile;
     }
 
+    /**
+     * @return ZipOutputFile
+     */
+    public function edit(){
+        return ZipOutputFile::openFromZipFile($this);
+    }
+
     /**
      * Check zip file signature
      *