code: function (name, clazz) {
          var extend = _cs.annotation(clazz, "extend");
          if (extend === null)
              return false;
          if (_cs.istypeof(extend) !== "clazz")
              return false;
          if (   _cs.istypeof(extend[name]) === "function"
              || (   _cs.istypeof(extend.prototype) === "object"
                  && _cs.istypeof(extend.prototype[name]) === "function"))
              return true;
          else
              return has_base(name, extend);
      }
docs: /*
  STEP 4: OPTIONALLY EXPLICITLY INHERIT FROM MIXIN CLASSES
   /*  internal utility method for determining whether a function
  exists somewhere in the inheritance chain