/**
	 * @param  $groupname
	 * @param  $description
	 * @return null|OpenStackNovaSecurityGroup
	 */
	function createSecurityGroup( $groupname, $description ) {
		$response = $this->novaConnection->create_security_group( $groupname, $description );
		if ( ! $response->isOK() ) {
			return null;
		}
		$securityGroup = new OpenStackNovaSecurityGroup( $response->body->securityGroupSet->item );
		$groupname = $securityGroup->getGroupName();
		$this->securityGroups["$groupname"] = $securityGroup;

		return $securityGroup;
	}