private function update_token(){

		$body = array(
			'grant_type' => 'refresh_token',
			'client_id' => $this->get_salesforce_consumer_key(),
			'client_secret' => $this->get_salesforce_consumer_secret(),
			'refresh_token' => $this->get_salesforce_refresh_token(),
		);

		if(is_array($body) && count($body)>0) {
			$body=http_build_query($body);
		}

		$response = wp_remote_post( $this->token_url, array( 'body' => $body ) );

		$token_request_data = json_decode($response['body'], true);
		if (empty($token_request_data))
			die("Couldn't decode '$token_request_data' as a JSON object");

		if (!isset($token_request_data['access_token'])||
		    !isset($token_request_data['instance_url']))
			die("Missing expected data from ".print_r($token_request_data, true));

		$this->set_salesforce_access_token($token_request_data);

	}