def METHOD_NAME(self):
    os.environ["JAVA_HOME"] = "/path/to/java"
    telem = telemetry.Telemetry()
    # no JAVA_HOME -> use the bundled JDK
    env = self.launcher._prepare_env(node_name="node0", java_home=None, telemetry=telem)
    # unmodified
    self.assertEqual(os.environ["PATH"], env["PATH"])
    self.assertIsNone(env.get("JAVA_HOME"))