code: public DnsNameResolverBuilder searchDomains(Iterable<String> searchDomains) {
          checkNotNull(searchDomains, "searchDomains");
  
          final List<String> list = new ArrayList<String>(4);
  
          for (String f : searchDomains) {
              if (f == null) {
                  break;
              }
  
              // Avoid duplicate entries.
              if (list.contains(f)) {
                  continue;
              }
  
              list.add(f);
          }
  
          this.searchDomains = list.toArray(new String[0]);
          return this;
      }
docs: Set the list of search domains of the resolver.
  
  @param searchDomains the search domains
  @return {@code this}