code: func (b *Build) Link() *Link {
  	if b.Builder == nil {
  		panic("invalid build")
  	}
  	num := b.Id
  	if b.Number != 0 {
  		num = int64(b.Number)
  	}
  	builder := b.Builder
  	return NewLink(
  		fmt.Sprintf("%d", num),
  		fmt.Sprintf("/p/%s/builders/%s/%s/%d", builder.Project, builder.Bucket, builder.Builder, num),
  		fmt.Sprintf("Build %d", num))
  }
docs: // Link is a self link to the build.