Function sp_trie::delta_trie_root

pub fn delta_trie_root<L: TrieConfiguration, I, A, B, DB, V>(
    db: &mut DB, 
    root: TrieHash<L>, 
    delta: I
) -> Result<TrieHash<L>, Box<TrieError<L>>> where
    I: IntoIterator<Item = (A, B)>,
    A: Borrow<[u8]>,
    B: Borrow<Option<V>>,
    V: Borrow<[u8]>,
    DB: HashDB<L::Hash, DBValue>, 

Determine a trie root given a hash DB and delta values.