code: public String getCpuRateInfo() {
          StringBuilder sb = new StringBuilder();
          synchronized (mCpuInfoEntries) {
              for (Map.Entry<Long, String> entry : mCpuInfoEntries.entrySet()) {
                  long time = entry.getKey();
                  sb.append(BlockInfo.TIME_FORMATTER.format(time))
                          .append(' ')
                          .append(entry.getValue())
                          .append(BlockInfo.SEPARATOR);
              }
          }
          return sb.toString();
      }
docs: Get cpu rate information
  
  @return string show cpu rate information