public function getAuthorizationToken()
    {
        $authorizationToken = "Client-ID {$this->provider->getClientId()}";

        if (! is_null($this->token)) {
            // Validate if the token object link to this class is expire
            // refresh it if it's the case
            if ($this->token->hasExpired()) {
                $this->refreshToken();
            }

            $authorizationToken = "Bearer {$this->token->getToken()}";
        }

        return $authorizationToken;
    }