public static void addNeighborChange(Level world, BlockPos sourcePos, BlockPos neighborPos) {
        assert currentRun != null;
        currentRun.neighborChanges.put(world, neighborPos);

        // Track source of change for first time a particular neighbor is changed
        if (!currentRun.neighborChangeSources.containsKey(neighborPos))
            currentRun.neighborChangeSources.put(neighborPos, sourcePos);
    }
Used when the propagator did not change signal, but a new connection may
have been established and signal needs recalculating
core/src/main/java/mrtjp/projectred/core/RedstonePropagator.java