docs: public List statistic() {
          List result = new LinkedList();
          for (Iterator iter = calls.keySet().iterator(); iter.hasNext();) {
              Object[] line = new Object[3];
              result.add(line);
              line[0] = iter.next();
              List times = (List) calls.get(line[0]);
              line[1] = times.size() / 2;
              int accTime = 0;
              for (Iterator it = times.iterator(); it.hasNext();) {
                  Long start = (Long) it.next();
                  Long end = (Long) it.next();
                  accTime += end - start;
              }
              line[2] = (long) accTime;
          }
          return result;
      }