Is there any method to get graph for one node

[nvoynov]

Hello,

Suppose, I have a big requirements dependencies graph with any of next variants:

user story -> use case -> func. requirement -> source file -> test source
use case -> test case -> test source

I have built a full requirements dependencies graph. Can I have subtree from this full tree for certain func. requirement, it predecessors use case and user story as well as depend source files and test sources? Is there any built-in method in this gem?