'Return a :class:`~scrapy.crawler.Crawler` object.
* If `crawler_or_spidercls` is a Crawler, it is returned as-is.
* If `crawler_or_spidercls` is a Spider subclass, a new Crawler
is constructed for it.
* If `crawler_or_spidercls` is a string, this function finds
a spider with this name in a Scrapy project (using spider loader),
then creates a Crawler instance for it.'

def create_crawler(self, crawler_or_spidercls):

    if isinstance(crawler_or_spidercls, Crawler):
        return crawler_or_spidercls
    return self._create_crawler(crawler_or_spidercls)
