In components/security/firewall.rst, in the Firewall and Security Context section, there are (at least) two errors:

1. use Symfony\Component\Security\SecurityContext should be Symfony\Component\Security\Core\SecurityContext

2. new SecurityContext() fails; it is missing two required parameters. If this is intentional, then some documentation should be provided to that effect.

An alternative (and possibly more useful) solution might be to suggest getting the security context from the container (e.g. saying $container->get('security.context')).