docs: public StackTraceElement[] filter(StackTraceElement[] target, boolean keepTop) {
          //TODO: profile
          //TODO: investigate "keepTop" commit history - no effect!
          final List<StackTraceElement> filtered = new ArrayList<StackTraceElement>();
          for (StackTraceElement element : target) {
              if (CLEANER.isIn(element)) {
                  filtered.add(element);
              }
          }
          StackTraceElement[] result = new StackTraceElement[filtered.size()];
          return filtered.toArray(result);
      }