" do         it "should set the class" do           @node_group.assigned_node_class_names = @node_class_a.name            @node_group.should be_valid           @node_group.errors.should be_empty           @node_group.node_classes.size.should == 0           @node_group.node_classes.should include(@node_class_a)         end       end        describe "with multiple 