docs: @SuppressWarnings("unchecked")
    public void add(T newValue) throws IOException {
      if (value instanceof Integer && newValue instanceof Integer) {
        value = (T) Integer.valueOf(value.intValue() + newValue.intValue());
      } else if (value instanceof Long && newValue instanceof Long) {
        value = (T) Long.valueOf(value.longValue() + newValue.longValue());
      } else if (value instanceof Float && newValue instanceof Float) {
        value = (T) Float.valueOf(value.floatValue() + newValue.floatValue());
      } else if (value instanceof Double && newValue instanceof Double) {
        value = (T) Double.valueOf(value.doubleValue() + newValue.longValue());
      } else {
        throw new IOException("incompatible NumberComparators");
      }
    }