docs: function(constructorFn, chainConstruct) {
          var instance = this;
          if (typeof constructorFn==='boolean') {
              chainConstruct = constructorFn;
              constructorFn = null;
          }
          (typeof chainConstruct === 'boolean') || (chainConstruct=DEFAULT_CHAIN_CONSTRUCT);
          instance.$$constrFn = constructorFn || NOOP;
          instance.$$chainConstructed = chainConstruct ? true : false;
          return instance;
      }