    public function get($key, $default = null, $deep = false)
    {
        if ($deep) {
            @trigger_error('Using paths to find deeper items in '.__METHOD__.' is deprecated since version 2.8 and will be removed in 3.0. Filter the returned value in your own code instead.', E_USER_DEPRECATED);
        }

        if (!$deep || false === $pos = strpos($key, '[')) {
            return array_key_exists($key, $this->parameters) ? $this->parameters[$key] : $default;
        }

        $root = substr($key, 0, $pos);
        if (!array_key_exists($root, $this->parameters)) {
            return $default;
        }

        $value = $this->parameters[$root];
        $currentKey = null;
        for ($i = $pos, $c = strlen($key); $i < $c; ++$i) {
            $char = $key[$i];

            if ('[' === $char) {
                if (null !== $currentKey) {
                    throw new \InvalidArgumentException(sprintf('Malformed path. Unexpected "[" at position %d.', $i));
                }

                $currentKey = '';
            } elseif (']' === $char) {
                if (null === $currentKey) {
                    throw new \InvalidArgumentException(sprintf('Malformed path. Unexpected "]" at position %d.', $i));
                }

                if (!is_array($value) || !array_key_exists($currentKey, $value)) {
                    return $default;
                }

                $value = $value[$currentKey];
                $currentKey = null;
            } else {
                if (null === $currentKey) {
                    throw new \InvalidArgumentException(sprintf('Malformed path. Unexpected "%s" at position %d.', $char, $i));
                }

                $currentKey .= $char;
            }
        }

        if (null !== $currentKey) {
            throw new \InvalidArgumentException(sprintf('Malformed path. Path must end with "]".'));
        }

        return $value;
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.