Function serialize_paths 

pub fn serialize_paths<'a, V, W, RZ>(
    rz: RZ,
    target: &mut W,
) -> Result<SerializationStats>
where
    V: TrieValue,
    RZ: ZipperReadOnlyConditionalIteration<'a, V>,
    W: Write,

Serializes each value’s path from the focus of rz into .paths data written to target