Cleanup, bugfixes

src/Dataset.php

@@ -11,10 +11,13 @@ class Dataset
     
     protected array $options;
 
-    public function __construct(string $identifier, array $options)
+    protected ?string $version;
+
+    public function __construct(string $identifier, array $options, ?string $version=null)
     {
         $this->identifier = $identifier;
         $this->options = $options;
+        $this->version = $version;
     }
 
     public function getIdentifier(): string
@@ -22,6 +25,11 @@ class Dataset
         return $this->identifier;
     }
 
+    public function getVersion(): ?string
+    {
+        return $this->version;
+    }
+
     public function open(): ReaderInterface
     {
         $filename = $this->options['filename'];