code: List<Proposition> traverseLinks(Link[] links,
              Proposition proposition,
              Map<Proposition, Set<Proposition>> forwardDerivations,
              Map<Proposition, Set<Proposition>> backwardDerivations,
              Map<UniqueId, Proposition> references,
              KnowledgeSourceCache ksCache) {
          return this.linkTraverser.traverseLinks(links, proposition,
                  forwardDerivations, backwardDerivations, references,
                  ksCache);
      }
docs: Traverses links from a proposition to a list of propositions.
  
  @param links the {@link Link}s to traverse.
  @param proposition the {@link Proposition} from which to start. Cannot be
  <code>null</code>.
  @param forwardDerivations map of propositions from raw data toward
  derived propositions.
  @param backwardDerivations map of propositions from derived propositions
  toward raw data.
  @param references a map of unique id to the corresponding proposition for
  propositions that are referred to by other propositions.
  @param knowledgeSource the {@link KnowledgeSource}.
  @return the list of {@link Propositions} at the end of the traversals.
  @throws KnowledgeSourceReadException if an error occurred reading from
  the knowledge source.