SimpleSAML_Auth_State::getPersistentAuthData PHP Method

    public static function getPersistentAuthData(array $state)
    {
        // save persistent authentication data
        $persistent = array();
        if (array_key_exists('PersistentAuthData', $state)) {
            foreach ($state['PersistentAuthData'] as $key) {
                if (isset($state[$key])) {
                    $persistent[$key] = $state[$key];
                }
            }
        }
        // add those that should always be included
        $mandatory = array('Attributes', 'Expire', 'LogoutState', 'AuthInstant', 'RememberMe', 'saml:sp:NameID');
        foreach ($mandatory as $key) {
            if (isset($state[$key])) {
                $persistent[$key] = $state[$key];
            }
        }
        return $persistent;
    }

 /**
  * Test the getPersistentAuthData() function.
  */
 public function testGetPersistentAuthData()
 {
     $mandatory = array('Attributes' => array(), 'Expire' => 1234, 'LogoutState' => 'logoutState', 'AuthInstant' => 123456, 'RememberMe' => true, 'saml:sp:NameID' => 'nameID');
     // check just mandatory parameters
     $state = $mandatory;
     $expected = $mandatory;
     $this->assertEquals($expected, SimpleSAML_Auth_State::getPersistentAuthData($state), 'Mandatory state attributes did not survive as expected' . print_r($expected, true));
     // check missing mandatory parameters
     unset($state['LogoutState']);
     unset($state['RememberMe']);
     $expected = $state;
     $this->assertEquals($expected, SimpleSAML_Auth_State::getPersistentAuthData($state), 'Some error occurred with missing mandatory parameters');
     // check additional non-persistent parameters
     $additional = array('additional1' => 1, 'additional2' => 2);
     $state = array_merge($mandatory, $additional);
     $expected = $mandatory;
     $this->assertEquals($expected, SimpleSAML_Auth_State::getPersistentAuthData($state), 'Additional parameters survived');
     // check additional persistent parameters
     $additional['PersistentAuthData'] = array('additional1');
     $state = array_merge($mandatory, $additional);
     $expected = $state;
     unset($expected['additional2']);
     unset($expected['PersistentAuthData']);
     $this->assertEquals($expected, SimpleSAML_Auth_State::getPersistentAuthData($state), 'Some error occurred with additional, persistent parameters');
     // check only additional persistent parameters
     $state = $additional;
     $expected = $state;
     unset($expected['additional2']);
     unset($expected['PersistentAuthData']);
     $this->assertEquals($expected, SimpleSAML_Auth_State::getPersistentAuthData($state), 'Some error occurred with additional, persistent parameters, and no mandatory ones');
 }