Function sp_trie::generate_trie_proof

pub fn generate_trie_proof<'a, L: TrieConfiguration, I, K, DB>(
    db: &DB, 
    root: TrieHash<L>, 
    keys: I
) -> Result<Vec<Vec<u8>>, Box<TrieError<L>>> where
    I: IntoIterator<Item = &'a K>,
    K: 'a + AsRef<[u8]>,
    DB: HashDBRef<L::Hash, DBValue>, 

Create a proof for a subset of keys in a trie.

The keys may contain any set of keys regardless of each one of them is included in the db.

For a key K that is included in the db a proof of inclusion is generated. For a key K that is not included in the db a proof of non-inclusion is generated. These can be later checked in verify_trie_proof.