void (@NotNull CompileContext context, ModuleChunk chunk) { FilesDelta currentDelta = getRoundDelta(NEXT_ROUND_DELTA_KEY, context); if (currentDelta == null) { // this is the initial round. // Need to make a snapshot of the FS state so that all builders in the chain see the same picture final List<FilesDelta> deltas = new SmartList<>(); for (ModuleBuildTarget target : chunk.getTargets()) { deltas.add(getDelta(target)); } currentDelta = new FilesDelta(deltas); } setRoundDelta(CURRENT_ROUND_DELTA_KEY, context, currentDelta); setRoundDelta(NEXT_ROUND_DELTA_KEY, context, new FilesDelta()); }