@asyncio.coroutine<EOL><INDENT>def miner_setExtra(self, data):<DEDENT>
return (yield from self.rpc_call('<STR_LIT>', [data]))<EOL>
https://github.com/ethereum/go-ethereum/wiki/Management-APIs#miner_setextra

        :param data: Extra data a miner can include when miner blocks
        :type data: str

        :rtype: bool