in src/main/java/org/apache/sling/jcr/jackrabbit/base/security/PrincipalProviderTracker.java [143:151]
private static boolean equals(Object object1, Object object2) {
if (object1 == object2) {
return true;
}
if ((object1 == null) || (object2 == null)) {
return false;
}
return object1.equals(object2);
}