Don't create a file with empty favorites

     * @param list a list of favorite controls. The list will be stored in the same order.

     */

    fun storeFavorites(structures: List<StructureInfo>) {

        if (structures.isEmpty() && !file.exists()) {

            // Do not create a new file to store nothing

            return

        }

        executor.execute {

            Log.d(TAG, "Saving data to file: $file")

            val atomicFile = AtomicFile(file)

import com.android.systemui.util.time.FakeSystemClock

import org.junit.After

import org.junit.Assert.assertEquals

import org.junit.Assert.assertFalse

import org.junit.Before

import org.junit.Test

import org.junit.runner.RunWith

        assertEquals(list, wrapper.readFavorites())

    }

    @Test

    fun testSaveEmptyOnNonExistingFile() {

        if (file.exists()) {

            file.delete()

        }

        wrapper.storeFavorites(emptyList())

        assertFalse(file.exists())

    }

}