Smarty v5 update test, initial code setup

src/Compile/Modifier/BCPluginWrapper.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Smarty\Compile\Modifier;
+
+class BCPluginWrapper extends Base {
+
+	private $callback;
+
+	public function __construct($callback) {
+		$this->callback = $callback;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function compile($params, \Smarty\Compiler\Template $compiler) {
+		return call_user_func($this->callback, $params, $compiler);
+	}
+}