protected function get_iauthority()
	{
		if ($this->iuserinfo !== null || $this->ihost !== null || $this->port !== null)
		{
			$iauthority = '';
			if ($this->iuserinfo !== null)
			{
				$iauthority .= $this->iuserinfo . '@';
			}
			if ($this->ihost !== null)
			{
				$iauthority .= $this->ihost;
			}
			if ($this->port !== null)
			{
				$iauthority .= ':' . $this->port;
			}
			return $iauthority;
		}
		else
		{
			return null;
		}
	}