'Logs given request.
Parameters
request : scrapy.http.Request
spider : scrapy.spiders.Spider'

def log(self, request, spider):

    if self.debug:
        msg = 'Filtered    duplicate    request:    %(request)s'
        self.logger.debug(msg, {'request': request}, extra={'spider': spider})
    elif self.logdupes:
        msg = 'Filtered    duplicate    request    %(request)s    -    no    more    duplicates    will    be    shown    (see    DUPEFILTER_DEBUG    to    show    all    duplicates)'
        self.logger.debug(msg, {'request': request}, extra={'spider': spider})
        self.logdupes = False
