pub fn decode(&'a self) -> Result<impl Iterator<Item=&'a B> + 'a, &'a [B]> {
            match &self.inner {
                Ok(encoded) => Ok(encoded.decode()),
                Err(symbols) => Err(symbols),
            }
        }
Returns either a decoding iterator, or just the bytes themselves.
differential-dataflow/src/trace/implementations/huffman_container.rs