Finalize the quoted argument matcher

Author: fabpot

src/Parser/QuotedArgumentMatcher.php

@@ -12,7 +12,7 @@
  * Double-quoted literals only accept the escaped backslash and quote;
  * interpolation and other escape sequences are dynamic values and never match.
  */
-class QuotedArgumentMatcher
+final class QuotedArgumentMatcher
 {
     private const LITERAL = '(?:\'(?<single>(?:\\\\.|[^\'\\\\])+)\'|"(?<double>(?:\\\\[\\\\"]|[^"\\\\$])+)")';
 
@@ -76,7 +76,7 @@ private function match(string $text, string $pattern): array
         return $arguments;
     }
 
-    protected function decode(string $raw, bool $single): string
+    private function decode(string $raw, bool $single): string
     {
         return $single
             ? strtr($raw, ['\\\\' => '\\', "\\'" => "'"])