src/Concerns/HasMiddleware.php
protected function getMiddleware(string $key = "", string $group = null, $default = null)
    {
        return $this->getMiddlewareGroup($group ?: $this->middlewareGroupId)->get($key, $default);
    }
protected function getMiddleware(string $key = "", string $group = null, $default = null)
    {
        return $this->getMiddlewareGroup($group ?: $this->middlewareGroupId)->get($key, $default);
    }
Retrieves the middleware by key and group with a variable fallback.

@param string $key
@param string|null $group
@param mixed $default
@return mixed