Function decode_holocene_base_fee 

pub fn decode_holocene_base_fee<H>(
    chain_spec: impl EthChainSpec + OpHardforks,
    parent: &H,
    timestamp: u64,
) -> Result<u64, EIP1559ParamError>
where
    H: BlockHeader,

Extracts the Holocene 1599 parameters from the encoded extra data from the parent header.

Caution: Caller must ensure that holocene is active in the parent header.

See also Base fee computation