Inner class overridden setProperty() calls outer class setProperty()

class InnerClassSetPropertyBugTest extends GroovyTestCase {
    def someProperty

    class InnerObject {
        def someProperty
        void setProperty(String property, Object newValue) {
            super.setProperty(property, newValue)
        }
    }

    void test() {
        def innerObject = new InnerObject()

        innerObject.someProperty = "abc"

        assert null == innerObject.someProperty 
        assert "abc" == someProperty
    }

}