### clickAndVerifyCheckbox
```kotlin
fun clickAndVerifyCheckbox() {
    composeTestRule.onNode(isToggleable()).performClick().assertIsOn()
}
```

### useUnmergedTree
```kotlin
fun useUnmergedTree() {
    composeTestRule.setContent {
        // Box is a semantically merging composable. All testTags of its
        // children are merged up into it in the merged semantics tree.
        Box(Modifier.testTag("box").padding(16.dp)) { Box(Modifier.testTag("icon").size(48.dp)) }
    }
    // Verify the position of the inner box. Without `useUnmergedTree`, the
    // test would check the position of the outer box (which is `(0, 0)`)
    // instead of the position of the inner box (which is `(16, 16)`).
    composeTestRule
        .onNodeWithTag("icon", useUnmergedTree = true)
        .assertLeftPositionInRootIsEqualTo(16.dp)
        .assertTopPositionInRootIsEqualTo(16.dp)
}
```