pipe.set(i, wrapper.get(0));
SIRStream child = wrapper.get(0);  pipe.set(i, child); child.setParent(pipe);
        void fuseChild(SIRPipeline pipe, int i) {            // I'm not sure that FuseAll.fuse removes the wrapper when            // it mutates 'pipe', so I'm removing it myself            SIRPipeline wrapper = FuseAll.fuse(pipe.get(i));            pipe.set(i, wrapper.get(0));        }