code: func (def *PackageChunkDef) strings() []*string {
  	out := []*string{
  		&def.Dir,
  		&def.File,
  		&def.VersionFile,
  	}
  	for i := range def.Exclude {
  		out = append(out, &def.Exclude[i])
  	}
  	return out
  }
docs: // strings return array of pointers to all strings in PackageChunkDef that can
  // contain ${var} variables.