src/Walker.php
public function walk()
    {
        if ($this->index < 0) {
            return $this->begin();
        }

        if (!$this->grid->hasColumn($this->index + 1)) {
            return $this->end() . $this->begin();
        }

        return $this->column();
    }
public function walk()
    {
        if ($this->index < 0) {
            return $this->begin();
        }

        if (!$this->grid->hasColumn($this->index + 1)) {
            return $this->end() . $this->begin();
        }

        return $this->column();
    }
Automatically walk throw the grid.

@return string