code: public static final List<Float> parsePercentiles(final String spec) {
      List<Float> rs = new ArrayList<Float>();
      int start_pos = spec.indexOf('[');
      int end_pos = spec.indexOf(']');
      if (start_pos == -1 || end_pos == -1) {
        throw new BadRequestException("Malformated percentile query paramater: " + spec);
      }
      
      String [] floats = Tags.splitString(spec.substring(start_pos + 1, end_pos), ',');
      for (String s : floats) {
        String trimed = s.trim();
        rs.add(Float.valueOf(trimed));
      }
      return rs;
    }
docs: Parse the "percentile" section of the query string and returns an list of
  float that contains the percentile calculation paramters
  <p>
  the format of the section: percentile[xx,yy,zz]
  </p>
  <p>
  xx, yy, zz are the floats
  </p>
  @param spec
  @return