static void register(Object lhs, Object rhs) {
        synchronized (EqualsBuilder.class) {
            if (getRegistry() == null) {
                REGISTRY.set(new HashSet<Pair<IDKey, IDKey>>());
            }
        }

        Set<Pair<IDKey, IDKey>> registry = getRegistry();
        Pair<IDKey, IDKey> pair = getRegisterPair(lhs, rhs);
        registry.add(pair);
    }
<p>
Registers the given object pair.
Used by the reflection methods to avoid infinite loops.
</p>

@param lhs <code>this</code> object to register
@param rhs the other object to register
android/android_framework/base/src/main/java/lang3/builder/EqualsBuilder.java