public function helpCommand()
    {
        $availableCommands = $this->getAvailableCommands();
        $longestCommandNameLength = max(
            array_map(
                function ($item) {
                    return strlen($item);
                },
                array_keys($availableCommands)
            )
        );

        $longestCommandNameLength += 4;
        foreach ($availableCommands as $command => $help) {
            $line = ''
                . self::ESCAPE . self::GREEN
                . str_pad($command, $longestCommandNameLength)
                . self::ESCAPE . self::NORMAL
                . $help;
            $this->outputLine($line);
        }
    }