Thread.setContextClassLoader creates an unnecessary RuntimePermission object each
time it is called when a SecurityManager is enabled:

 SecurityManager sm = System.getSecurityManager();
     if (sm != null) {
            sm.checkPermission(new RuntimePermission("setContextClassLoader"));
     }
 
This is unnecessary, a singleton should be used instead like the objects
in sun.security.util.SecurityConstants, ex:

public static final RuntimePermission SET_CONTEXT_CLASSLOADER_PERMISSION =
    new RuntimePermission("setContextClassLoader");