          ...
  
      def crawled_similar(self, signature):
          """Determine if we've already crawled a page matching the given signature"""
          ...
  
  
  class Page(object):
  
      def __init__(self, url, contents, child_urls):
 
</s> remove         ...
 </s> add         pass </s> remove         ...
 </s> add         pass </s> remove         # ...
 </s> add         pass </s> remove         ...
 </s> add         pass </s> remove     def park_vehicle(self, vehicle):  # ...
    def remove_vehicle(self):  # ... </s> add 
        pass
          ...
  
      def crawled_similar(self, signature):
          """Determine if we've already crawled a page matching the given signature"""
        pass
  
  
  class Page(object):
  
      def __init__(self, url, contents, child_urls):
keep keep keep keep replace keep keep keep keep keep
 Convert all .py files to be valid Python (#98) 
solutions/system_design/web_crawler/web_crawler_snippets.py