SimBackend.go

// Create a new SimulatedBackend with a default allocation
backend := backends.NewSimulatedBackend(core.DefaultGenesisBlock().Alloc, 9000000)
bal, err := backend.BalanceAt(ctx, common.HexToAddress("0x000"), nil)
		
// Create a meaningful allocation with a faucet secret key
faucetSK, err := crypto.GenerateKey()
faucetAddr := crypto.PubkeyToAddress(faucetSK.PublicKey)
addr := map[common.Address]core.GenesisAccount{
	common.BytesToAddress([]byte{1}): {Balance: big.NewInt(1)}, // ECRecover
	common.BytesToAddress([]byte{2}): {Balance: big.NewInt(1)}, // SHA256
	common.BytesToAddress([]byte{3}): {Balance: big.NewInt(1)}, // RIPEMD
	common.BytesToAddress([]byte{4}): {Balance: big.NewInt(1)}, // Identity
	common.BytesToAddress([]byte{5}): {Balance: big.NewInt(1)}, // ModExp
	common.BytesToAddress([]byte{6}): {Balance: big.NewInt(1)}, // ECAdd
	common.BytesToAddress([]byte{7}): {Balance: big.NewInt(1)}, // ECScalarMul
	common.BytesToAddress([]byte{8}): {Balance: big.NewInt(1)}, // ECPairing
	faucetAddr:                       {Balance: new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(9))},
}
alloc := core.GenesisAlloc(addr)
backend := backends.NewSimulatedBackend(alloc, 9000000)