code: func (bc *BlockChain) GetReceiptsByHash(hash common.Hash) types.Receipts {
  	if receipts, ok := bc.receiptsCache.Get(hash); ok {
  		return receipts.(types.Receipts)
  	}
  	number := rawdb.ReadHeaderNumber(bc.db, hash)
  	if number == nil {
  		return nil
  	}
  	receipts := rawdb.ReadReceipts(bc.db, hash, *number, bc.chainConfig)
  	if receipts == nil {
  		return nil
  	}
  	bc.receiptsCache.Add(hash, receipts)
  	return receipts
  }
docs: // GetReceiptsByHash retrieves the receipts for all transactions in a given block.