Cannot set shape of a rail

sign.getWorld().getBlockAt(blockx,blocky + 2,blockz);
Rail r = (Rail) b.getBlockData();

//Above 2 lines are working (tested with prints already)
r.setShape(Rail.Shape.NORTH_EAST);


Why the setShape isnt working?

 

what do you mean by "updating the block"
what do i need to do

 

"updated the block" with b#getState#update(); , no use

 

Code:

Inital BlockState :
[16:50:39] [Server thread/INFO]: CraftBlockData{Block{minecraft:rail}[shape=north_west]}

Final BlockState:
[16:50:39] [Server thread/INFO]: org.bukkit.craftbukkit.v1_15_R1.block.CraftBlockState@ba48f438

 

no it did NOT update

inital state = final state

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

yea but i dont know h0w to set block data to a specific shape like north#west the syntax

 

b#setBlockData #arga# argb#
what to write in arg a and arg b

if i want to set the rail to northeast