Fixed duplicate function def

src/DatasetManager.php

@@ -27,11 +27,6 @@ class DatasetManager
         return self::$datasets;
     }
 
-    public function getDataset(string $identifier): Dataset
-    {
-        return self::$dataset[$identifier];
-    }
-
     public function openDataset(string $identifier): ReaderInterface
     {
         return $this->getDataset($identifier)->open();