gas

type Estimator interface {

	// In Ethereum without EIP-1559, the gas price (and gas cap) would be the
	// recommended GWEI-per-gas required to get a transaction into one of the
	// next few blocks (because blocks happen a lot faster). In Ethereum with
	// EIP1559, the gas price and gas cap would be back calculated given the gas
	// cap and an estimate of the current gas base.
	//
	// The assumption is that the total gas cost will be gasLimit * gasPrice <
	// gasLimit * gasCap. If chain nodes give back values based on different
	// assumptions, then the values must be normalised as needed.
	EstimateGas(context.Context) (gasPrice, gasCap pack.U256, err error)
}