code: func (sf StaticFile) AsStaticSymlink() (s StaticSymlink, ok bool) {
  	if sf.b.ss.Type == "symlink" {
  		return StaticSymlink{sf}, true
  	}
  
  	return
  }
docs: // AsStaticSymlink returns the StaticFile as a StaticSymlink if the
  // StaticFile represents a symlink. Othwerwise, it returns the zero
  // value of StaticSymlink and false.