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: codecs.rs
    path of file: ./repos/kafka-rust/src
    
    the code of the file until where you have to start completion: use std::default::Default;
use std::io::{Read, Write};

use crate::error::{Error, Result};
use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};

// Helper macro to safely convert an usize expression into a signed
// integer.  If the conversion is no
    
    fn decode<T: Read>(&mut self, buffer: &mut T) -> Result<()> {
        let mut length: i16 = 0;
        if let Err(e) = decode!(buffer, read_i16, &mut length) {
            return Err(e);
        }
        if length <= 0 {
            return Ok(());
        }
        self.reserve(length as usize);
        let _ = buffer.take(length as u64).read_to_string(self);
        if self.len() != length as usize {
            return Err(Error::UnexpectedEOF);
        }
        Ok(())
    }