### Question:
FrameTransformTree { @VisibleForTesting FrameTransform transformToRoot(GraphName resolvedSource) { FrameTransform result = getLatest(resolvedSource); if (result == null) { return null; } while (true) { FrameTransform resultToParent = lookUp(result.getTargetFrame(), result.getTime()); if (resultToParent == null) { return result; } Transform transform = resultToParent.getTransform().multiply(result.getTransform()); GraphName resolvedTarget = resultToParent.getTargetFrame(); result = new FrameTransform(transform, resolvedSource, resolvedTarget, result.getTime()); } } FrameTransformTree(NameResolver nameResolver); void update(geometry_msgs.TransformStamped transformStamped); FrameTransform lookUp(GraphName source); FrameTransform get(String source); FrameTransform lookUp(GraphName source, Time time); FrameTransform get(String source, Time time); FrameTransform transform(GraphName source, GraphName target); FrameTransform transform(String source, String target);  }### Answer:
@Test public void testTransformBazToRoot() { updateFrameTransformTree(); checkBazToFooTransform(frameTransformTree.transformToRoot(nameResolver.resolve("baz"))); }
@Test public void testTransformFuzToRoot() { updateFrameTransformTree(); checkFuzToFooTransform(frameTransformTree.transformToRoot(nameResolver.resolve("fuz"))); }