trait NumberFromAttr: FromStr<Err = ParseIntError> {}

impl NumberFromAttr for u8 {}
// ...
impl NumberFromAttr for i64 {}

impl<T: NumberFromAttr> TryFromAttribute for T {
  fn try_from_attr(
    attribute_name: impl Into<String>,
    attribute: Option<AttributeValue>,
  ) -> Result<Self, DBItemError> {
    match &attribute {
      Some(AttributeValue::N(numeric_str)) => {
        parse_integer(attribute_name, numeric_str)
      }
      Some(_) => Err(DBItemError::new(
        attribute_name.into(),
        Value::AttributeValue(attribute),
        DBItemAttributeError::IncorrectType,
      )),
      None => Err(DBItemError::new(
        attribute_name.into(),
        Value::AttributeValue(attribute),
        DBItemAttributeError::Missing,
      )),
    }
  }
}