code: public void processExternalEdge(final int role, final int src) {
          externalQueue.add(new IRoleQueueEntry() {
              /**
               * Serialisation version.
               */
              private static final long serialVersionUID = 1L;
  
              @Override
              public int getR() {
                  return role;
              }
  
              @Override
              public int getB() {
                  return src;
              }
          });
      }
docs: Triggers the processing of an edge based on events that happened in another {@link Context}.
  
  @param role
  @param src