After Symfony calls ``createToken()``, it will then call ``supportsToken()``

on your class (and any other authentication listeners) to figure out who should

handle the token. This is just a way to allow several authentication mechanisms

to be used for the same firewall (that way, you can for instance first try

to authenticate the user via a certificate or an API key and fall back to

a form login).

Mostly, you just need to make sure that this method returns ``true`` for a

token that has been created by ``createToken()``. Your logic should probably

look exactly like this example.