func env(block *types.Block, eth core.Backend) *environment {
state := state.New(block.Root(), eth.StateDb())
env := &environment{
totalUsedGas: new(big.Int),
state: state,
block: block,
family: set.New(),
uncles: set.New(),
coinbase: state.GetOrNewStateObject(block.Coinbase()),
}
return env
}
