text: function _classCallCheck(instance, Constructor) {
      if (!(instance instanceof Constructor)) throw new TypeError("Cannot call a class as a function");
  }
  function _getPrototypeOf(o) {
      return _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) {
          return o.__proto__ || Object.getPrototypeOf(o);
      }, _getPrototypeOf(o);
  }
  function _inherits(subClass, superClass) {
      if ("function" != typeof superClass && null !== superClass) throw new TypeError("Super expression must either be null or a function");
      subClass.prototype = Object.create(superClass && superClass.prototype, {
          constructor: {
              value: subClass,
              writable: !0,
              configurable: !0
          }
      }), superClass && _setPrototypeOf(subClass, superClass);
  }
  function _possibleConstructorReturn(self, call) {
      return call && ("object" === _typeof(call) || "function" == typeof call) ? call : (function(self) {
          if (void 0 === self) throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
          return self;
      })(self);
  }
  function _setPrototypeOf(o, p) {
      return _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) {
          return o.__proto__ = p, o;
      }, _setPrototypeOf(o, p);
  }
  var TwoLevels, _typeof = function(obj) {
      return obj && "undefined" != typeof Symbol && obj.constructor === Symbol ? "symbol" : typeof obj;
  }, Base = function() {
      "use strict";
      _classCallCheck(this, Base);
  }, Derived = function(Base) {
      "use strict";
      function Derived() {
          return _classCallCheck(this, Derived), _possibleConstructorReturn(this, _getPrototypeOf(Derived).apply(this, arguments));
      }
      return _inherits(Derived, Base), Derived;
  }(Base), Derived2 = function(Derived) {
      "use strict";
      function Derived2() {
          return _classCallCheck(this, Derived2), _possibleConstructorReturn(this, _getPrototypeOf(Derived2).apply(this, arguments));
      }
      return _inherits(Derived2, Derived), Derived2;
  }(Derived), A = function() {
      "use strict";
      _classCallCheck(this, A);
  }, B = function(A) {
      "use strict";
      function B() {
          return _classCallCheck(this, B), _possibleConstructorReturn(this, _getPrototypeOf(B).apply(this, arguments));
      }
      return _inherits(B, A), B;
  }(A), A2 = function() {
      "use strict";
      _classCallCheck(this, A2);
  }, B2 = function(A2) {
      "use strict";
      function B2() {
          return _classCallCheck(this, B2), _possibleConstructorReturn(this, _getPrototypeOf(B2).apply(this, arguments));
      }
      return _inherits(B2, A2), B2;
  }(A2), A3 = function() {
      "use strict";
      _classCallCheck(this, A3);
  }, B3 = function(A3) {
      "use strict";
      function B3() {
          return _classCallCheck(this, B3), _possibleConstructorReturn(this, _getPrototypeOf(B3).apply(this, arguments));
      }
      return _inherits(B3, A3), B3;
  }(A3);
  !function(TwoLevels) {
      var A1 = function() {
          "use strict";
          _classCallCheck(this, A1);
      }, B = function(A) {
          "use strict";
          function B() {
              return _classCallCheck(this, B), _possibleConstructorReturn(this, _getPrototypeOf(B).apply(this, arguments));
          }
          return _inherits(B, A), B;
      }(A1), A21 = function() {
          "use strict";
          _classCallCheck(this, A21);
      }, B2 = function(A2) {
          "use strict";
          function B2() {
              return _classCallCheck(this, B2), _possibleConstructorReturn(this, _getPrototypeOf(B2).apply(this, arguments));
          }
          return _inherits(B2, A2), B2;
      }(A21), A31 = function() {
          "use strict";
          _classCallCheck(this, A31);
      }, B3 = function(A3) {
          "use strict";
          function B3() {
              return _classCallCheck(this, B3), _possibleConstructorReturn(this, _getPrototypeOf(B3).apply(this, arguments));
          }
          return _inherits(B3, A3), B3;
      }(A31);
  }(TwoLevels || (TwoLevels = {
  }));
  