code: public void removeReference(Reference reference) throws GreenPepperServerException
      {
          if(!references.contains(reference))
          {
              throw new GreenPepperServerException( GreenPepperServerErrorKey.REFERENCE_NOT_FOUND, "Reference not found");
          }
  
          references.remove(reference);
          reference.setSpecification(null);
      }
docs: <p>removeReference.</p>
  
  @param reference a {@link com.greenpepper.server.domain.Reference} object.
  @throws com.greenpepper.server.GreenPepperServerException if any.