diff --git a/www/lib/Test/DB/TestDB.php b/www/lib/Test/DB/TestDB.php
new file mode 100644
index 00000000..32ee7615
--- /dev/null
+++ b/www/lib/Test/DB/TestDB.php
@@ -0,0 +1,58 @@
+<?php
+
+/*
+ * TEST sets for DB::IO
+ */
+
+namespace Test\DB;
+
+use CoreLibs\DB\IO;
+
+class TestDB
+{
+	/** @var IO */
+	private $db;
+	/** @var array<mixed> */
+	private $config;
+
+	/**
+	 * Undocumented function
+	 */
+	public function __construct()
+	{
+		$this->config = [
+			'db_name' => $_ENV['DB_NAME_TEST'] ?? '',
+			'db_user' => $_ENV['DB_USER_TEST'] ?? '',
+			'db_pass' => $_ENV['DB_PASS_TEST'] ?? '',
+			'db_host' => $_ENV['DB_HOST_TEST'] ?? '',
+			'db_port' => 5432,
+			'db_schema' => 'public',
+			'db_type' => 'pgsql',
+			'db_encoding' => '',
+			'db_ssl' => 'allow'
+		];
+		$this->db = new IO($this->config);
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return void
+	 */
+	private function testDBa(): void
+	{
+		$this->db->dbInfo();
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return void
+	 */
+	public function testRunDB(): void
+	{
+		$this->testDBa();
+	}
+}
+
+// __ENB__
diff --git a/www/lib/Test/Test.php b/www/lib/Test/Test.php
index 8b74b393..0848202d 100644
--- a/www/lib/Test/Test.php
+++ b/www/lib/Test/Test.php
@@ -8,8 +8,12 @@ declare(strict_types=1);
 
 namespace Test;
 
+use Test\DB;
+
 class Test
 {
+	/** @var DB\TestDB */
+	private $test_db;
 
 	public function __construct()
 	{
@@ -17,6 +21,9 @@ class Test
 		$this->testPrivate();
 		$this->testProtected();
 		$this->testPublic();
+
+		// call intern
+		$this->test_db = new DB\TestDB();
 	}
 
 	public function __destruct()
@@ -56,6 +63,16 @@ class Test
 		$string = 'TEST Public';
 		return $string;
 	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return void
+	 */
+	public function testClasses(): void
+	{
+		$this->test_db->testRunDB();
+	}
 }
 
 // __END__