Function unpadded_hash 

pub fn unpadded_hash<'a, I>(iter: I) -> [BabyBearElem; 8]
where
    I: Iterator<Item = &'a BabyBearElem>,

Perform an unpadded hash of a vector of elements. Because this is unpadded collision resistance is only true for vectors of the same size. If the size is variable, this is subject to length extension attacks.