### SpatialMainPanelSample
```kotlin
public fun SpatialMainPanelSample() {
    @Composable
    fun MainPanelContent() {
        Text("Main panel")
    }
    @Composable
    fun AppContent() {
        // 2D Content rendered to the main panel.
        MainPanelContent()
        // Spatial content rendered in full space mode.
        Subspace {
            SpatialRow {
                SpatialPanel { Text("Spatial panel") }
                SpatialMainPanel()
            }
        }
    }
}
```