think\console\Input::parseArgument PHP Method

    private function parseArgument($token)
    {
        $c = count($this->arguments);
        if ($this->definition->hasArgument($c)) {
            $arg = $this->definition->getArgument($c);
            $this->arguments[$arg->getName()] = $arg->isArray() ? [$token] : $token;
        } elseif ($this->definition->hasArgument($c - 1) && $this->definition->getArgument($c - 1)->isArray()) {
            $arg = $this->definition->getArgument($c - 1);
            $this->arguments[$arg->getName()][] = $token;
        } else {
            throw new \RuntimeException('Too many arguments.');
        }
    }