code: def get_chunk_meta_item(self, chunk_meta, grp, pug, chk):
          
          num_chk = self.envs["NUM_CHK"]
          num_pu = self.envs["NUM_PU"]
          index = grp * num_pu * num_chk + pug * num_chk + chk
          return chunk_meta[index]
docs: Get item of chunk meta table