code: @NonNull
      private String activeFlags(@NonNull SparseArray<String> valueNames, int bitfield) {
          final StringBuilder result = new StringBuilder();
  
          // Look for masks, apply it an retrieve the masked value
          for (int i = 0; i < valueNames.size(); i++) {
              final int maskValue = valueNames.keyAt(i);
              if (valueNames.get(maskValue).endsWith(SUFFIX_MASK)) {
                  final int value = bitfield & maskValue;
                  if (value > 0) {
                      if (result.length() > 0) {
                          result.append('+');
                      }
                      result.append(valueNames.get(value));
                  }
              }
          }
          return result.toString();
      }
docs: Some fields contain multiple value types which can be isolated by
  applying a bitmask. That method returns the concatenation of active
  values.
  
  @param valueNames The array containing the different values and names for this
  field. Must contain mask values too.
  @param bitfield   The bitfield to inspect.
  @return The names of the different values contained in the bitfield,
  separated by '+'.