code: func (w *Wrapper) showComponent(pkgs []*PackageInfo) string {
  	result := []string{}
  	inCycle := map[string]bool{}
  	for _, pkg := range pkgs {
  		inCycle[pkg.ComputedPackage] = true
  	}
  	for _, pkg := range pkgs {
  		for _, other := range pkg.ImportedPackageComputedNames() {
  			if inCycle[other] {
  				result = append(result, fmt.Sprintf(" %s --> %s", pkg.ComputedPackage, other))
  				for _, f := range pkg.Files {
  					for _, depName := range f.Deps {
  						dep := w.infos[depName]
  						if dep.ComputedPackage == other {
  							result = append(result, fmt.Sprintf("  %s imports %s", f.Name, dep.Name))
  						}
  					}
  				}
  			}
  		}
  	}
  	return strings.Join(result, "\n")
  }
docs: // showComponent returns a string describing why a strongly connected
  // component is strongly connected.