public function client()
	{
		if (isset($this->client)) {
			return $this->client ? $this->client : null;
		}
		
		$client_id = $this->clientId();
		if (!$client_id) {
			$this->client = false;
			return null;
		}
		
		$client = $this->fetchClient($client_id);
		if ($client) {
			$this->client = $client;
		}
		else {
			$this->client = false;
		}
		
		return $this->client ? $this->client : null;
	}