Minecraft 16w39a, Minecraft 16w39b, Minecraft 16w39c, Minecraft 16w40a
an observer bloc and a redstone dust
The observer blocs works very well.
It has an input and an output.
But, if you place a redstone dust next to a side which is no input or output, the redstone will connect to the bloc...
not so horrible, but it could be embarrassing for some redstone builders !
thanks for reading,
hope this was useful
Wulfhartus, the Clumsy Lord