Function solana_vote_program::vote_state::update_node

pub fn update_node<S: BuildHasher>(
    vote_account: &KeyedAccount, 
    node_pubkey: &Pubkey, 
    signers: &HashSet<Pubkey, S>, 
    clock: &Clock
) -> Result<(), InstructionError>

Update the node_pubkey, requires signature of the authorized voter