code: func readFile(file string) ([]byte, error) {
  	theFile, err := os.Open(file)
  	if err != nil {
  		return nil, err
  	}
  	defer theFile.Close()
  
  	byteValue, err := ioutil.ReadAll(theFile)
  	if err != nil {
  		return nil, err
  	}
  
  	return byteValue, nil
  }
docs: // readFile opens a given file and reads it contents into a stream of bytes