Setting callback is mandatory, why?

[Frenchcooc]

Hi!

I'm getting an error when calling nanoajax.ajax() WITHOUT setting a callback function.

Code :

nanoajax.ajax({url:'/some-get-url'})

Error :

Uncaught TypeError: a is not a function
    at XMLHttpRequest.<anonymous> (nanoajax.js:2)

It may arrives that handling XHR response is not necessary. As a consequence, setting a callback should not be necessary.

A condition to check if a is a function would take some bytes, but be useful.

Thanks!