src/Web/Sessions/Session.php
public function remove($key)
    {
        $this->open();
        $data = $this->data;
        if (isset($data[$key])) {
            unset($data[$key]);
        }
        $this->data = $data;
    }
public function remove($key)
    {
        $this->open();
        $data = $this->data;
        if (isset($data[$key])) {
            unset($data[$key]);
        }
        $this->data = $data;
    }
Removes a session variable.
@param string $key the name of the session variable to be removed