import "github.com/ethereum/go-ethereum/common" // create a new Ethereum address from a hexadecimal string addr := common.HexToAddress("0x1234567890123456789012345678901234567890") // get the hexadecimal representation of the address hex := addr.Hex() // "0x1234567890123456789012345678901234567890"In the example above, we import the `common` package and create a new Ethereum address using the `HexToAddress()` function. We then call the `Hex()` method on the address to get its hexadecimal representation. The `common.Address` type is a part of the `go-ethereum` package library.