You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: decoder.rs
    path of file: ./repos/y-crdt/yrs/src/updates
    
    the code of the file until where you have to start completion: use crate::block::ClientID;
use crate::*;
use crate::encoding::read::{Read, Error, Cursor};
use std::sync::Arc;

/// A trait that can be implemented by any other type in order to support lib0 decoding capability.
pub trait Decode: Sized {
    fn decode<D: Decoder>(decoder: &mut D) -> Result<Self, Error>;

    /// Helper function for decoding 1st version of lib0 encoding.
    fn decode_v1(data: &[u8]) -> Result<Self, Error> {
        let mut decoder = DecoderV1::from(data);
        Self::decode(&mut decoder)
    }

    /// Helper function for decoding 2nd version of lib0 encoding.
    fn decode_v2(data: &[u8]) -> Result<Self, Error> {
        let mut decoder = DecoderV2::new(Cursor::new(data))?;
        Self::decode(&mut decoder)
    }
}

/// Trait used by lib0 decoders. Natively lib0 encoding supports two versions:
///
/// 1. 1st version (implemented in Yrs) uses simple optimization techniques like var int encoding.
/// 2. 2nd version optimizes bigger batches of blocks by using run-length encoding.
///
/// Both of these define a common set of operations defined in this trait.  
pub trait Decoder: Read {
    /// Reset the value of current delete set state.
    fn reset_ds_cur_val(&mut self);

    /// Read next [DeleteSet] clock value.
    fn read_ds_clock(&mut self) -> Result<u32, Error>;

    /// Read the number of clients stored in encoded [DeleteSet].
    fn read_ds_len(&
    
    pub fn new(mut cursor: Cursor<'a>) -> Result<Self, Error> {
        if cursor.has_content() {
            // read feature flag - currently unused
            let _: u8 = cursor.read_u8()?;
        }
        let mut idx = cursor.next;
        let buf = cursor.buf;

        let key_clock_buf = Self::read_buf(buf, &mut idx)?;
        let client_buf = Self::read_buf(buf, &mut idx)?;
        let left_clock_buf = Self::read_buf(buf, &mut idx)?;
        let right_clock_buf = Self::read_buf(buf, &mut idx)?;
        let info_buf = Self::read_buf(buf, &mut idx)?;
        let string_buf = Self::read_buf(buf, &mut idx)?;
        let parent_info_buf = Self::read_buf(buf, &mut idx)?;
        let type_ref_buf = Self::read_buf(buf, &mut idx)?;
        let len_buf = Self::read_buf(buf, &mut idx)?;
        let cursor = Cursor {
            buf: &buf[idx..],
            next: 0,
        };
        Ok(DecoderV2 {
            cursor,
            ds_curr_val: 0,
            keys: Vec::new(),
            key_clock_decoder: IntDiffOptRleDecoder::new(Cursor::new(key_clock_buf)),
            client_decoder: UIntOptRleDecoder::new(Cursor::new(client_buf)),
            left_clock_decoder: IntDiffOptRleDecoder::new(Cursor::new(left_clock_buf)),
            right_clock_decoder: IntDiffOptRleDecoder::new(Cursor::new(right_clock_buf)),
            info_decoder: RleDecoder::new(Cursor::new(info_buf)),
            string_decoder: StringDecoder::new(Cursor::new(string_buf))?,
            parent_info_decoder: RleDecoder::new(Cursor::new(parent_info_buf)),
            type_ref_decoder: UIntOptRleDecoder::new(Cursor::new(type_ref_buf)),
            len_decoder: UIntOptRleDecoder::new(Cursor::new(len_buf)),
        })
    }