@validate(addr=int, val=int)<EOL><INDENT>def write_byte(self, addr, val):<DEDENT>
self._set_addr(addr)<EOL>if SMBUS.i2c_smbus_write_byte(self._fd, ffi.cast("<STR_LIT>", val)) == -<NUM_LIT:1>:<EOL><INDENT>raise IOError(ffi.errno)<EOL><DEDENT>
write_byte(addr, val)

        Perform SMBus Write Byte transaction.