Registers an event for the current visitor to the flood control mechanism.
string $name: The name of an event. To prevent unintended name clashes, it is recommended to use the module name first in the event name, optionally followed by a dot and the actual event name (e.g. "mymodule.my_event").
int $window: (optional) Number of seconds before this event expires. Defaults to 3600 (1 hour). Typically uses the same value as the isAllowed() $window parameter. Expired events are purged on cron run to prevent the flood table from growing indefinitely.
string $identifier: (optional) Unique identifier of the current user. Defaults to the current user's IP address).
public function register($name, $window = 3600, $identifier = NULL);