TwitterOAuth\Auth\AuthAbstract::validateCredentials PHP Method

    protected function validateCredentials($credentials)
    {
        $credentials = array_filter($credentials);
        $keys = array_keys($credentials);
        $diff = array_diff($this->requiredCredentials, $keys);
        if (!empty($diff)) {
            throw new MissingCredentialsException('Missing Credentials: ' . implode($diff, ', '));
        }
        unset($credentials, $keys, $diff);
    }