Posisi karakter pembantu berkulit hitam, Calpurnia, sebagai figur ibu bagi anak-anak berkulit putih: analisis karakter melalui konsep mammy figure pada To Kill a Mockingbird = The Position of a black maid, Calpurnia, as a mother figure of white children: a character analysis of the mammy figure concept in To Kill a Mockingbird