new_contents: __author__ = 'mengpeng'
  
  #Example settings for building a single spider
  #If don't use 'args', default args will be used.
  SPIDER = {'name': 'MySpider',
            'scraper': {'name': 'DefaultScraper',
                        'args': {'debug': True}},
            'frontier': {'name': 'BFSFrontier',
                         'args': {'rules': ['((http|ftp|https)://)(([a-zA-Z0-9\._-]+\.[a-zA-Z]{2,6})|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(:[0-9]{1,4})*(/[a-zA-Z0-9\&%_\./-~-]*)?']}},
            'handlers': [{'name': 'TempHandler',
                          'args': {'path': './tmp/', 'overwrite': True}}],
            'persist': {'name': 'MongoPersist',
                        'args': {'db': 'pycrawler', 'collection': 'MySpider-items'}}}
  
  #Example settings for building a driver with several spiders
  DRIVER = {'name': 'MyCrawler',
            'spiders': [
                {'name': 'spider1',
                 'scraper': {'name': 'DefaultScraper',
                             'args': {'debug': True}},
                 'frontier': {'name': 'BFSFrontier',
                              'args': {'rules': ['((http|ftp|https)://)(([a-zA-Z0-9\._-]+\.[a-zA-Z]{2,6})|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(:[0-9]{1,4})*(/[a-zA-Z0-9\&%_\./-~-]*)?']}},
                 'handlers': [{'name': 'TempHandler',
                               'args': {'path': './tmp/', 'overwrite': True}}],
                 'persist': {'name': 'MongoPersist',
                             'args': {'db': 'pycrawler', 'collection': 'MySpider-items'}}},
                {'name': 'spider2',
                 'scraper': {'name': 'DefaultScraper'},
                 'frontier': {'name': 'BFSFrontier'},
                 'handlers': [
                     {'name': 'TempHandler'},
                     {'name': 'LinkHandler'}],
                 'persist': {'name': 'MongoPersist'}}
            ]}
subject: add setting examples