public void setTypeHandler(Memory.Type type, Handler handler) {
        if (handler == null) {
            typeHandlers.remove(type);
        } else {
            typeHandlers.put(type, handler);
        }
    }
Finds first occurrence of unicode character and returns its index or {@code -1} otherwise.
exts/jphp-json-ext/src/main/java/org/develnext/jphp/json/gson/MemorySerializer.java