public void setDomain(ProtectionDomain d) {
        domain = d;
    }
Sets the protection domain for the classes handled by this class
loader.  Without registering an appropriate protection domain,
the program loaded by this loader will not work with a security
manager or a signed jar file.
agent-module/profiler-test/src/main/java/com/navercorp/pinpoint/profiler/test/classloader/TransformClassLoader.java