code: public Node getLastBuiltOn() {
          // where was it built on?
          AbstractBuild b = getLastBuild();
          if(b==null)
              return null;
          else
              return b.getBuiltOn();
      }
docs: Gets the {@link Node} where this project was last built on.
  
  @return
  null if no information is available (for example,
  if no build was done yet.)