code: @Override
      public TrustGraphNodeId getNextHop(final TrustGraphNodeId priorNeighbor) {
          if (priorNeighbor != null) {
              return routingTable.get(priorNeighbor);
          }
          else {
              return null;
          }
      }
docs: Determine the next TrustGraphNodeId in a route containing
  a given neighbor as the prior node.  The next hop is the
  TrustGraphNodeId paired with the given neighbor in the table.
  
  @param priorNeighbor the prior node on the route
  @return the next TrustGraphNodeId to route a message to
  or null if the next hop cannot be determined.
  @see RandomRoutingTable.getNextHop(TrustGraphNodeId)