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: blocks.rs
    path of file: ./repos/nih-plug/src/buffer
    
    the code of the file until where you have to start completion: //! Per-block per-channel per-sample iterators.

use std::marker::PhantomData;

#[cfg(feature = "simd")]
use std::simd::{LaneCount, Simd, SupportedLaneCount};

use super::SamplesIter;

/// An iterator over all samples in the buffer, slicing over th
    
    pub fn iter_mut(&mut self) -> BlockChannelsIter<'slice, 'sample> {
        BlockChannelsIter {
            buffers: self.buffers,
            current_block_start: self.current_block_start,
            current_block_end: self.current_block_end,
            current_channel: 0,
            _marker: self._marker,
        }
    }