realpath and bug fix

Author: doganoo

src/FileSystem/DirHandler.php

@@ -132,7 +132,7 @@ public function list(): array {
      * @param string $path
      * @return array
      */
-    function _list(string $path): array {
+    private function _list(string $path): array {
         $result = [];
         $scan = glob($path . '/*');
         foreach ($scan as $item) {
@@ -144,4 +144,13 @@ function _list(string $path): array {
         }
         return $result;
     }
+
+    /**
+     * @return string|null
+     */
+    public function toRealPath(): ?string {
+        $realpath = \realpath($this->path);
+        if (false === $realpath) return null;
+        return $realpath;
+    }
 }