code: func DeleteHeader(db ethdb.Writer, hash common.Hash, number uint64) {
  	deleteHeaderWithoutNumber(db, hash, number)
  	if err := db.Delete(headerNumberKey(hash)); err != nil {
  		log.Crit("Failed to delete hash to number mapping", "err", err)
  	}
  }
docs: // DeleteHeader removes all block header data associated with a hash.