code: public static Affordance afford(Object invocationValue) {
  
  		ControllerLinkBuilder linkBuilder = linkTo(invocationValue);
  
  		Assert.isTrue(linkBuilder.getAffordances().size() == 1, "A base can only have one affordance, itself");
  
  		return linkBuilder.getAffordances().get(0);
  	}
docs: Extract a {@link Link} from the {@link ControllerLinkBuilder} and look up the related {@link Affordance}. Should
  only be one.
  
  <pre>
  Link findOneLink = linkTo(methodOn(EmployeeController.class).findOne(id)).withSelfRel()
  .andAffordance(afford(methodOn(EmployeeController.class).updateEmployee(null, id)));
  </pre>
  
  This takes a link and adds an {@link Affordance} based on another Spring MVC handler method.
  
  @param invocationValue
  @return