code: func (ec *Client) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
  	var r *types.Receipt
  	err := ec.c.CallContext(ctx, &r, "eth_getTransactionReceipt", txHash)
  	if err == nil {
  		if r == nil {
  			return nil, ethereum.NotFound
  		}
  	}
  	return r, err
  }
docs: // TransactionReceipt returns the receipt of a transaction by transaction hash.
  // Note that the receipt is not available for pending transactions.