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