   /*@_spi(Testing)*/ public func findSwiftDepsToRecompileWhenNodesChange<Nodes: Sequence>(
     _ nodes: Nodes
   ) -> Set<SwiftDeps>
-  where Nodes.Element == Node
   {
     let affectedNodes = Tracer.findPreviouslyUntracedUsesOf(
       defs: nodes,

    tracedNodes.insert(n)
  }
  func ensureGraphWillRetraceDependents<Nodes: Sequence>(of nodes: Nodes)
  where Nodes.Element == Node
  {
    nodes.forEach { tracedNodes.remove($0) }
  }

    fatalError("unimplmemented, writing dot file of dependency graph")
  }
}

