code: public Set<Version> getDiscoveredVersionsForDomain(String domain) {
          Set<Version> result = new HashSet<>();
          if (hasExceptionForDomain(domain)) {
              result.addAll(exceptionsByDomain.get(domain).getDiscoveredVersions());
          }
          return result;
      }
docs: Returns the set of versions which were discovered for a given domain.
  
  @param domain
  the domain for which to return the set of versions which were found by that domain.
  
  @return the set of discovered versions for the given domain, or an empty set if no discovered versions are
  available for that domain. Will never be <code>null</code>.