src/core/Session.php
public function removeAll(): array
    {
        $res = [];
        foreach ($this->getKeys() as $key) {
            $res[$key] = $this->remove($key);
        }
        return $res;
    }
public function removeAll(): array
    {
        $res = [];
        foreach ($this->getKeys() as $key) {
            $res[$key] = $this->remove($key);
        }
        return $res;
    }
It clears the session by removing all stored variables.
@return mixed[] The array of removed vars.