code: protected function drawBorder($left, $middle, $right)
  	{
  		$width = $this->geometry->getWidthButBorders();
  
  		$border = str_repeat(static::BORDER_Y, $width);
  
  		$this->replaceUtf8($border, $left, 0);
  		$this->replaceUtf8($border, $middle, floor($width / 2));
  		$this->replaceUtf8($border, $right, $width - 1);
  
  		$this->drawBordered($border);
  	}
docs: Draw a border with the given bendings.
  
  @author	Andrea Marco Sartori
  @param	string	$left
  @param	string	$middle
  @param	string	$right
  @return	void