prototype of caching RubyString objects created from Java string literals

gistfile1.java

class RubyString {

    //...

    private final ObjectProxyCache<IRubyObject,RubyString> stringCache = 
    new ObjectProxyCache<Object,RubyString>(ObjectProxyCache.ReferenceType.SOFT) {

        public IRubyObject allocateProxy(CharSequence str, RubyClass clazz) {
            return RubyString.newString(clazz.getRuntime(), str);
        }
    };
    
    public RubyString cachedString(CharSequence s){
        return stringCache.get(s);
    }
    
    // ...
}