code: func ApplyDAOHardFork(statedb *state.StateDB) {
  	// Retrieve the contract to refund balances into
  	if !statedb.Exist(params.DAORefundContract) {
  		statedb.CreateAccount(params.DAORefundContract)
  	}
  
  	// Move every DAO account and extra-balance account funds into the refund contract
  	for _, addr := range params.DAODrainList() {
  		statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr))
  		statedb.SetBalance(addr, new(big.Int))
  	}
  }
docs: // ApplyDAOHardFork modifies the state database according to the DAO hard-fork
  // rules, transferring all balances of a set of DAO accounts to a single refund
  // contract.