src/TokenStream.php
public function at($pos)
    {
        if (!isset($this->stream[$pos])) {
            throw new \InvalidArgumentException(sprintf('Position "%d" is invalid', $pos));
        }

        return $this->stream[$pos];
    }
public function at($pos)
    {
        if (!isset($this->stream[$pos])) {
            throw new \InvalidArgumentException(sprintf('Position "%d" is invalid', $pos));
        }

        return $this->stream[$pos];
    }
{@inheritdoc}