system/Pager/PagerRenderer.php
protected function updatePages(int $count = null)
	{
		if (is_null($count))
		{
			return;
		}

		$this->first = $this->current - $count > 0 ? (int) ($this->current - $count) : 1;
		$this->last  = $this->current + $count <= $this->pageCount ? (int) ($this->current + $count) : (int) $this->pageCount;
	}
protected function updatePages(int $count = null)
	{
		if (is_null($count))
		{
			return;
		}

		$this->first = $this->current - $count > 0 ? (int) ($this->current - $count) : 1;
		$this->last  = $this->current + $count <= $this->pageCount ? (int) ($this->current + $count) : (int) $this->pageCount;
	}
Updates the first and last pages based on $surroundCount,
which is the number of links surrounding the active page
to show.

@param integer|null $count The new "surroundCount"