object reference in Kotlin
Object expression is a structure that creates a single instance of an object: ``` val coords = object { var x = 10 var y = 10 } ``` It is often used as a substitution to a Java anonymous class: ``` window.addMouseListener(object : MouseAdapter() { override fun mouseClicked(e: MouseEvent) { /* ...*/ } override fun mouseEntered(e: MouseEvent) { /* ...*/ } }) ```