Function deserialize_empty_string_or_string 

pub fn deserialize_empty_string_or_string<'de, D>(
    deserializer: D,
) -> Result<Option<String>, D::Error>
where
    D: Deserializer<'de>,

deserialize an optional String where None is represented as an empty string

Errors

returns an error if the value can not be interpreted as null or a String