class Foo { def feedItemId def bar } def l1 = new Foo() l1.feedItemId = "hello" l1.bar = "same" def l2 = new Foo() l2.feedItemId = "world" l2.bar = "same" println("feedItemId" in (l1.properties - l2.properties)) println(l1.properties - l2.properties) println(l2.properties - l1.properties)