Reverted fix for implicitly nullable parameter declarations

src/GraphicsState.php

@@ -26,12 +26,10 @@ class GraphicsState
     /**
      * @param Matrix|null $ctm
      */
-    public function __construct($ctm = null)
+    public function __construct(?Matrix $ctm = null)
     {
         if ($ctm === null) {
             $ctm = new Matrix();
-        } elseif (!($ctm instanceof Matrix)) {
-            throw new \InvalidArgumentException('$ctm must be an instance of Fpdi\\Matrix or null');
         }
 
         $this->ctm = $ctm;

src/PdfParser/Type/PdfDictionary.php

@@ -106,20 +106,15 @@ public static function create(array $entries = [])
      * @return PdfNull|PdfType
      * @throws PdfTypeException
      */
-    public static function get($dictionary, $key, $default = null)
+    public static function get($dictionary, $key, ?PdfType $default = null)
     {
-        if ($default !== null && !($default instanceof PdfType)) {
-            throw new \InvalidArgumentException('Default value must be an instance of PdfType or null');
-        }
         $dictionary = self::ensure($dictionary);
 
         if (isset($dictionary->value[$key])) {
             return $dictionary->value[$key];
         }
 
-        return $default === null
-            ? new PdfNull()
-            : $default;
+        return $default ?? new PdfNull();
     }
 
     /**

src/PdfParser/Type/PdfStream.php

@@ -35,11 +35,8 @@ class PdfStream extends PdfType
      * @return self
      * @throws PdfTypeException
      */
-    public static function parse(PdfDictionary $dictionary, StreamReader $reader, $parser = null)
+    public static function parse(PdfDictionary $dictionary, StreamReader $reader, ?PdfParser $parser = null)
     {
-        if ($parser !== null && !($parser instanceof PdfParser)) {
-            throw new \InvalidArgumentException('$parser must be an instance of PdfParser or null');
-        }
         $v = new self();
         $v->value = $dictionary;
         $v->reader = $reader;