Prepare for skeleton

src/StaticPHP/Skeleton/ExecutorGenerator.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace StaticPHP\Skeleton;
+
+use StaticPHP\Exception\ValidationException;
+use StaticPHP\Runtime\Executor\Executor;
+
+class ExecutorGenerator
+{
+    public function __construct(protected string $class)
+    {
+        if (!is_a($class, Executor::class, true)) {
+            throw new ValidationException('Executor class must extend ' . Executor::class);
+        }
+    }
+}