code: func (b *backendInstance) EthBalanceAt(ctx context.Context,
  	owner common.Address) (*big.Int, error) {
  	ctx2, cancel := b.addTimeout(ctx)
  	defer cancel()
  
  	return b.conn.ethClient().BalanceAt(ctx2, owner, nil)
  }
docs: // EthBalanceAt returns the wei balance of the given account.