public function border() {
		if (!isset($this->_border)) {
			$this->_border = $this->_characters['corner'];
			foreach ($this->_widths as $width) {
				$this->_border .= str_repeat($this->_characters['line'], $width + 2);
				$this->_border .= $this->_characters['corner'];
			}
		}

		return $this->_border;
	}