src/Collection.php
public function valid()
    {
        if ($this->items === null) {
            return false;
        }
        $key = key($this->items);
        return ($key !== null && $key !== false);
    }
public function valid()
    {
        if ($this->items === null) {
            return false;
        }
        $key = key($this->items);
        return ($key !== null && $key !== false);
    }
Checks if current position is valid.

@return boolean