public function connect($username = null, $password = null, $anonymous = false, $server = null)
{
$this->initiateLdapConnection($server);
$username = $this->usernameFormatter->getUsername($username ?: $this->config->getUsername());
$password = $password ?: $this->config->getPassword();
$this->bind($username, $password, $anonymous);
$this->lastActivity = new \DateTime();
return $this;
}