code: func (l *Lambda) UpdateFunctionCode(in *lambda.UpdateFunctionCodeInput) (*lambda.FunctionConfiguration, error) {
  	res, err := l.GetFunction(&lambda.GetFunctionInput{
  		FunctionName: in.FunctionName,
  	})
  
  	if err != nil {
  		return nil, err
  	}
  
  	size := uint64(len(in.ZipFile))
  	checksum := utils.Sha256(in.ZipFile)
  	remoteChecksum := *res.Configuration.CodeSha256
  	remoteSize := uint64(*res.Configuration.CodeSize)
  
  	if checksum != remoteChecksum {
  		l.create("function", *in.FunctionName, map[string]interface{}{
  			"size": fmt.Sprintf("%s -> %s", humanize.Bytes(remoteSize), humanize.Bytes(size)),
  		})
  	}
  
  	out := &lambda.FunctionConfiguration{
  		Version: aws.String("$LATEST"),
  	}
  
  	return out, nil
  }
docs: // UpdateFunctionCode stub.