code: public static Rect unflattenFromString(String str) {
          Matcher matcher = FLATTENED_PATTERN.matcher(str);
          if (!matcher.matches()) {
              return null;
          }
          return new Rect(Integer.parseInt(matcher.group(1)),
                  Integer.parseInt(matcher.group(2)),
                  Integer.parseInt(matcher.group(3)),
                  Integer.parseInt(matcher.group(4)));
      }
docs: Returns a Rect from a string of the form returned by {@link #flattenToString},
  or null if the string is not of that form.
  
  @param str string
  
  @return rect