code: def parse_scratches(self):
          
          lx_doc = self.html_doc()
          if not self.__blocks:
              self.__pl_blocks(lx_doc)
  
          for t in ['aw_scr', 'h_scr']:
              ix = 'away' if t == 'aw_scr' else 'home'
              self.scratches[ix] = self.__clean_pl_block(self.__blocks[t])
  
          return self if self.scratches else None
docs: Parse the home and away healthy scratches
  
          :returns: ``self`` on success, ``None`` otherwise