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: actions.go
    path of file: ./repos/juju/acceptancetests/repository/trusty/fill-logs/actions
    
    the code of the file until where you have to start completion: package main

import (
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
)

func main() {
	if err := run(os.Args); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}

func run(args []string) error {
	if len(args) != 2 {
		return fmt.Errorf("expected exactly one argument, the action name")
	}
	switch args[1] {
	case "fill-unit":
		return fillUnit()
	case "fill-machine":
		return fillMachine()
	case "unit-size":
		return unitLogSizes()
	case "machine-size":
		return
    
func fillLog(w io.Writer) error {
	megs, err := getMegs()
	if err != nil {
		return err
	}
	bytes := megs * 1024 * 1024
	total := 0

	for total < bytes {
		// technically, the log file will be bigger than asked for, since it
		// prepends a bunch of stuff to each log call, but this guarantees we've
		// put *at least* this much data in the log, which should guarantee a
		// rotation.
		n, err := fmt.Fprintln(w, lorem)
		if err != nil {
			return fmt.Errorf("error writing to log: %s", err)
		}
		total += n
	}
	return nil
}