pub fn get_optional_str<'a, S: BuildHasher>(
json_block: &'a HashMap<&str, JSONValue<'_, S>, S>,
field: &str,
) -> Result<Option<&'a str>, ParseJsonError>
pub fn get_optional_str<'a, S: BuildHasher>(
json_block: &'a HashMap<&str, JSONValue<'_, S>, S>,
field: &str,
) -> Result<Option<&'a str>, ParseJsonError>