Make getSubfieldValues public.

Author: rudolfbyker

src/Fields/Field.php

@@ -156,7 +156,7 @@ protected function clean($value, $options = [])
      * @return string[]
      *   The values that were contained in the requested subfields.
      */
-    protected function getSubfieldValues($codes)
+    public function getSubfieldValues($codes)
     {
         if (!is_array($codes)) {
             $codes = [$codes];