code: private AttributeValue extractValueFor(String name) throws AttributeException {
  		final AttributeValue value;
  		if (this.cache.containsKey(name)) {
  			value = this.cache.get(name);
  		} else {
  			value = loadValue(name);
  			this.cache.put(name, value);
  		}
  		return value;
  	}
docs: Replies the value associated to the specified name.