OneLogin_Saml2_Utils::getExpireTime PHP Method

    public static function getExpireTime($cacheDuration = null, $validUntil = null)
    {
        $expireTime = null;
        if ($cacheDuration !== null) {
            $expireTime = self::parseDuration($cacheDuration, time());
        }
        if ($validUntil !== null) {
            if (is_int($validUntil)) {
                $validUntilTime = $validUntil;
            } else {
                $validUntilTime = self::parseSAML2Time($validUntil);
            }
            if ($expireTime === null || $expireTime > $validUntilTime) {
                $expireTime = $validUntilTime;
            }
        }
        return $expireTime;
    }

 /**
  * Tests the getExpireTime method of the OneLogin_Saml2_Utils
  *
  * @covers OneLogin_Saml2_Utils::getExpireTime
  */
 public function testGetExpireTime()
 {
     $this->assertNull(OneLogin_Saml2_Utils::getExpireTime());
     $this->assertNotNull(OneLogin_Saml2_Utils::getExpireTime('PT1393462294S'));
     $this->assertEquals('1418186371', OneLogin_Saml2_Utils::getExpireTime('PT1393462294S', '2014-12-10T04:39:31Z'));
     $this->assertEquals('1418186371', OneLogin_Saml2_Utils::getExpireTime('PT1393462294S', 1418186371));
     $this->assertNotEquals('1418186371', OneLogin_Saml2_Utils::getExpireTime('PT1393462294S', '2012-12-10T04:39:31Z'));
 }