code: function(clazz) {
          if (this !== clazz) {
              // detect class
              if (clazz.clazz === this.clazz) {
                  for (var p = this.$parent; p !== null; p = p.$parent) {
                      if (p === clazz) {
                          return true;
                      }
                  }
              } else { // detect interface
                  if (this.$parents[clazz.$hash$] === clazz) {
                      return true;
                  }
              }
          }
          return false;
      }
docs: Tests if the class inherits the given class or interface.
  @param  {zebkit.Class | zebkit.Interface} clazz a class or interface.
  @return {Boolean} true if the class or interface is inherited with
  the class.
  @method  isInherit
  @for  zebkit.Class