Added return types for 8-1 compatibility Iterator implementations

src/VCR/Storage/AbstractStorage.php

@@ -68,7 +68,7 @@ public function __construct(string $cassettePath, string $cassetteName, string $
      *
      * @return array<string,mixed>|null parsed current record
      */
-    public function current()
+    public function current(): mixed
     {
         return $this->current;
     }

src/VCR/Storage/Blackhole.php

@@ -35,10 +35,9 @@ public function key(): int
         throw new \BadMethodCallException('Not implemented');
     }
 
-    /** @return array<mixed>|null */
-    public function next(): ?array
+    /** @return void */
+    public function next(): void
     {
-        return null;
     }
 
     public function rewind(): void

src/VCR/Storage/Yaml.php

@@ -88,7 +88,7 @@ public function rewind(): void
         $this->position = 0;
     }
 
-    public function valid()
+    public function valid(): bool
     {
         if (null === $this->current) {
             $this->next();

tests/Unit/Storage/AbstractStorageTest.php

@@ -51,7 +51,7 @@ public function next(): void
     {
     }
 
-    public function valid()
+    public function valid(): bool
     {
         return (bool) $this->position;
     }