https://github.com/ethereum/wiki/wiki/JSON-RPC#db_puthex

        DEPRECATED

def db_putHex(self, db_name, key, value):
        """https://github.com/ethereum/wiki/wiki/JSON-RPC#db_puthex

        DEPRECATED
        """
        warnings.warn('deprecated', DeprecationWarning)
        if not value.startswith('0x'):
            value = add_0x(value)
        return (yield from self.rpc_call('db_putHex', [db_name, key, value]))