Does anyone know how to use 'expect' function within JSBin template ?

[![enter image description here](https://i.stack.imgur.com/2L1BW.png)](https://i.stack.imgur.com/2L1BW.png)

The function which I have written on the page is just a sample one but the main priority is is resolve `"Reference error: expect is not defined"`

Any help on this would be really appreciated.