def scrape(&blk)
      self.url_array = self.get_index unless self.url_array
      blk = Proc.new{|x| x} if blk.nil?
      self.scrape_from_list(self.url_array, blk)
    end
def scrape(&blk)
      self.url_array = self.get_index unless self.url_array
      blk = Proc.new{|x| x} if blk.nil?
      self.scrape_from_list(self.url_array, blk)
    end
This is the main user-facing method for a basic scraper.
 Call +scrape+ with a block; this block will be called on
 the text of each instance page, (and optionally, its URL and its index
 in the list of instance URLs returned by +get_index+).