Action Node.hx

Can’t find actionnode.hx, in Armory0.5_2.79\Armory\armsdk\armory\Sources\armory\logicnode, where all nodes haxe files are supposed to be.
There is Action Node(In Variable list) in blender but can’t find it haxe file, is it created or is it just placeholder?
If it created then, where is it and what do it do?
And while I am here what do Dynamic node(In Variable list) and Scene Root(Variable) node do?