public function createPlatformEndpoint($platformApplicationArn, $token, $userData = null) {
		if(empty($platformApplicationArn) || empty($token)) {
			throw new InvalidArgumentException('Must supply a PlatformApplicationArn & Token to create platform endpoint');
		}

		$attributes = array(
			'PlatformApplicationArn' => $platformApplicationArn,
			'Token' => $token
		);

		if(!empty($userData)) {
			$attributes['CustomUserData'] = $userData;
		}

		$response = $this->_request('CreatePlatformEndpoint', $attributes);

		return strval($response->CreatePlatformEndpointResult->EndpointArn);
	}