Returns code at a given address.
eth_getCode:params[0]: The address.params[1]: Block identifier. Can be an integer block number or a string tag: βlatestβ, βearliestβ, or βpendingβ.β0x600160008035811a818181146012578301005b601b6001356025565b8060005260206000f35b600060078202905091905056β.