Function sp_trie::read_child_trie_value_with

pub fn read_child_trie_value_with<L, Q, DB>(
    keyspace: &[u8],
    db: &DB,
    root_slice: &[u8],
    key: &[u8],
    query: Q
) -> Result<Option<Vec<u8>>, Box<TrieError<L>>>where
    L: TrieConfiguration,
    Q: Query<L::Hash, Item = DBValue>,
    DB: HashDBRef<L::Hash, DBValue>,

Read a value from the child trie with given query.