protected function fillDefaults($key, $value)
    {
        if (
            ($key === MessageDefaults::USER || $key === MessageDefaults::CHANNEL) &&
            (! is_null($this->getTarget()))
        ) {
            return;
        }

        if ($suffix = $this->studlyCase($key)) {
            $getMethod = 'get'.$suffix;
            $setMethod = 'set'.$suffix;
            if (
                method_exists($this, $getMethod) &&
                is_null($this->{$getMethod}()) &&
                method_exists($this, $setMethod)
            ) {
                $this->{$setMethod}($value);
            }
        }
    }