@ApiStatus.Internal
  public @NotNull FilesDelta getEffectiveFilesDelta(@NotNull CompileContext context, BuildTarget<?> target) {
    if (target instanceof ModuleBuildTarget) {
      // multiple compilation rounds are applicable to ModuleBuildTarget only
      final FilesDelta lastRoundDelta = getRoundDelta(CURRENT_ROUND_DELTA_KEY, context);
      if (lastRoundDelta != null) {
        return lastRoundDelta;
      }
    }
    return getDelta(target);
  }
@ApiStatus.Internal
  public @NotNull FilesDelta getEffectiveFilesDelta(@NotNull CompileContext context, BuildTarget<?> target)