let B = function B() { "use strict"; }; let A = /*#__PURE__*/function (_B) { "use strict"; babelHelpers.inheritsLoose(A, _B); function A(track) { var _this; if (track !== undefined) _this = _B.call(this, track) || this;else _this = _B.call(this) || this; return babelHelpers.assertThisInitialized(_this); } return A; }(B);