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: common.rs
    path of file: ./repos/Symphonia/symphonia-format-riff/src
    
    the code of the file until where you have to start completion: // Symphonia
// Copyright (c) 2019-2022 The Project Symphonia Developers.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.

/// `PacketInfo` helps to simulate packetization over a number of blocks of data.
/// In case the codec is blockless the block size equals one full audio frame in bytes.
use std::marker::PhantomData;

use symphonia_core::audio::Channels;
use symphonia_core::codecs::CodecParameters;
use symphonia_core::codecs::CodecType;
use symphonia_core::errors::{decode_error, end_of_stream_error, Error, Result};
use symphonia_core::formats::prelude::*;
use symphonia_core::io::{MediaSourceStream, ReadBytes};

use log::{debug, info};

pub enum ByteOrder {
    LittleEndian,
    BigEndian,
}

/// The maximum number of frames that will be in a packet.
/// Since there are no real packets in AIFF, this is arbitrary, used same value as MP3.
const MAX_FRAMES_PER_PACKET: u64 = 1152;

/// `ParseChunkTag` implements `parse_tag` to map between the 4-byte chunk identifier and the
/// enumeration
pub trait ParseChunkTag: Sized {
    fn parse_tag(tag: [u8; 4], len: u32) -> Option<Self>;
}

pub enum NullChunks {}

impl ParseChunkTag for NullChunks {
    fn parse_tag(_tag: [u8; 4], _len: u32) -> Option<Self> {
        None
    }
}

pub fn fix_channel_mask(mut channel_mask: u32, n_channels: u16) -> u32 {
    let channel_diff = n_channels as i32 - channel_mask.count_ones() as i32;

    if channel_diff != 0 {
        info!("Channel mask not set correctly, channel positions may be incorrect!");
    }

    // Check that the number of ones in the channel mask match the number of channels.
    if channel_diff > 0 {
        // Too few ones in mask so add extra ones above the most si
    
    pub fn next<B: ReadBytes>(&mut self, reader: &mut B) -> Result<Option<T>> {
        // Loop until a chunk is recognized and returned, or the end of stream is reached.
        loop {
            // Align to the next 2-byte boundary if not currently aligned.
            if self.consumed & 0x1 == 1 {
                reader.read_u8()?;
                self.consumed += 1;
            }

            // Check if there are enough bytes for another chunk, if not, there are no more chunks.
            if self.consumed + 8 > self.len {
                return Ok(None);
            }

            // Read tag and len, the chunk header.
            let tag = reader.read_quad_bytes()?;

            let len = match self.byte_order {
                ByteOrder::LittleEndian => reader.read_u32()?,
                ByteOrder::BigEndian => reader.read_be_u32()?,
            };

            self.consumed += 8;

            // Check if the ChunkReader has enough unread bytes to fully read the chunk.
            //
            // Warning: the formulation of this conditional is critical because len is untrusted
            // input, it may overflow when if added to anything.
            if self.len - self.consumed < len {
                // When ffmpeg encodes wave to stdout the riff (parent) and data chunk lengths are
                // (2^32)-1 since the size can't be known ahead of time.
                if !(self.len == len && len == u32::MAX) {
                    debug!(
                        "chunk length of {} exceeds parent (list) chunk length",
                        String::from_utf8_lossy(&tag)
                    );
                    return decode_error("riff: chunk length exceeds parent (list) chunk length");
                }
            }

            // The length of the chunk has been validated, so "consume" the chunk.
            self.consumed = self.consumed.saturating_add(len);

            match T::parse_tag(tag, len) {
                Some(chunk) => return Ok(Some(chunk)),
                None => {
                    // As per the RIFF spec, unknown chunks are to be ignored.
                    info!(
                        "ignoring unknown chunk: tag={}, len={}.",
                        String::from_utf8_lossy(&tag),
                        len
                    );

                    reader.ignore_bytes(u64::from(len))?
                }
            }
        }
    }