A theme in Jetpack Compose example

ThemeExample.kt

@Composable
fun ContactList() {
    MyTheme {
       // Todos os composables deste bloco irão herdar o aspecto visual de MyTheme
       Text("Hello world") 
    }
}

@Composable
fun MyTheme(
    darkTheme: Boolean = isSystemInDarkTheme(),
    content: @Composable () -> Unit
) {
    MaterialTheme(
        colors = if (darkTheme) DarkColors else LightColors,
        /*...*/
        content = content
    )
}