code: @Override
    @SuppressWarnings("unchecked")
    public void visit(final Visitable visitable) {
      if (visitable instanceof Identifiable) {
        ((Identifiable) visitable).setId(null);
      }
    }
docs: Visits any Visitable object implementing the Identifiable interface, clearing the Identifiable objects identifier.
  
  @param visitable the Visitable object visited by this Visitor.
  @see org.cp.elements.lang.Identifiable#setId(Comparable)
  @see org.cp.elements.lang.Visitable