Update BodyStructurePart.php

Author: stevebauman

src/BodyStructurePart.php

@@ -51,7 +51,9 @@ protected static function parse(array $tokens, string $partNumber): static
                 ? MimeParameterParser::parse($tokens[2]->toKeyValuePairs())
                 : [],
             id: static::tokenValueAt($tokens, 3),
-            description: Str::decodeMimeHeader(static::tokenValueAt($tokens, 4) ?? ''),
+            description: is_null($description = static::tokenValueAt($tokens, 4))
+                 ? null
+                 : Str::decodeMimeHeader($description),
             encoding: static::tokenValueAt($tokens, 5),
             size: static::tokenIntValueAt($tokens, 6),
             lines: static::tokenIntValueAt($tokens, 7),
@@ -66,7 +68,9 @@ protected static function parse(array $tokens, string $partNumber): static
      */
     protected static function tokenValueAt(array $tokens, int $index): ?string
     {
-        $token = $tokens[$index] ?? null;
+        if (is_null($token = $tokens[$index] ?? null)) {
+            return null;
+        }
 
         if (! $token instanceof Token || $token instanceof Nil) {
             return null;
@@ -84,7 +88,7 @@ protected static function tokenIntValueAt(array $tokens, int $index): ?int
     {
         $value = static::tokenValueAt($tokens, $index);
 
-        return $value === null ? null : (int) $value;
+        return is_null($value) ? null : (int) $value;
     }
 
     /**