data.kt

FirebaseDatabase.getInstance().reference.child("test").child("Android").apply {
    setValue(null)
    push().setValue(mapOf("hoge" to 1, "fuga" to 5))
    push().setValue(mapOf("hoge" to 2, "fuga" to 4))
    push().setValue(mapOf("hoge" to 3, "fuga" to 3))
    push().setValue(mapOf("hoge" to 4, "fuga" to 2))
    push().setValue(mapOf("hoge" to 5, "fuga" to 1))
}