code: func (b *Build) BuilderLink() *Link {
  	if b.Builder == nil {
  		panic("Invalid build")
  	}
  	builder := b.Builder
  	return NewLink(
  		builder.Builder,
  		fmt.Sprintf("/p/%s/builders/%s/%s", builder.Project, builder.Bucket, builder.Builder),
  		fmt.Sprintf("Builder %s in bucket %s", builder.Builder, builder.Bucket))
  }
docs: // BuilderLink returns a link to the builder in b.