docs: public byte[] readBytes() throws IORuntimeException {
  		long len = file.length();
  		if (len >= Integer.MAX_VALUE) {
  			throw new IORuntimeException("File is larger then max array size");
  		}
  
  		byte[] bytes = new byte[(int) len];
  		FileInputStream in = null;
  		int readLength;
  		try {
  			in = new FileInputStream(file);
  			readLength = in.read(bytes);
  			if(readLength < len){
  				throw new IOException(StrUtil.format("File length is [{}] but read [{}]!", len, readLength));
  			}
  		} catch (Exception e) {
  			throw new IORuntimeException(e);
  		} finally {
  			IoUtil.close(in);
  		}
  
  		return bytes;
  	}