# Update 16 ## week 16 updates This week I focused majorly on implementing the ideas which I got from nethermind implementation: * major task is to create an `ExecutionWitness` struct which will be responsible for managing `accessed_leaves`, `accesed_stems`, `accessed_branch` stores which will be used for determining warm-cold gas costs changes according to eip-4762. * this will include functions to add gas cost of witness access during execution of various opcodes whose gas-costs needs to be changed according to eip-4762. * all this functions will then lead to creation of new interpreter functions for each opcodes. * these interpreter functions will then replace the existing gas-cost function in the main evm loop which executes opcodes. ## week 17 roadmap Next week I will focus on implementing this changes and going through geth implementation as well.