code: func (u UnionCategoryExpander) Expand(category string) ([]schema.GroupResource, bool) {
  	ret := []schema.GroupResource{}
  	ok := false
  
  	// Expand the category for each CategoryExpander in the list and merge/combine the results.
  	for _, expansion := range u {
  		curr, currOk := expansion.Expand(category)
  
  		for _, currGR := range curr {
  			found := false
  			for _, existing := range ret {
  				if existing == currGR {
  					found = true
  					break
  				}
  			}
  			if !found {
  				ret = append(ret, currGR)
  			}
  		}
  		ok = ok || currOk
  	}
  
  	return ret, ok
  }
docs: // Expand fulfills CategoryExpander