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    Dayang Sumbi was a beautiful and kind hearted princess, but sometimes she was very lazy. Her hobby was weaving cloth. One day her weaving tool fell. Tumang, a male dog, came to bring her tool back to her. As she had promised, she married him. Tumang was actually a man who had been cursed by a witch to become a dog. But sometimes he could turn back to a normal man. Dayang Sumbi and Tumang got one son. His name was Sangkuriang. He did not know that Tumang was his father because he was a dog whenever he was with him. Tumang always accompanied Sangkuriang whenever he went hunting in the woods.

    When he was twelve years old. Dayang Sumbi asked Sangkuriang to bring her a deer's heart. But after many days in the woods, he could not find a deer. He did not want to disappoint his mother, so he killed Tumang and brought his heart home and gave it to his mother. Because of her love to Tumang, Dayang Sumbi knew it was his heart, not a deer's heart. She got very angry at Sangkuriang. She hit him with a piece of wood on his forehead, and told him to go away. Badly wounded, Sangkuriang left her and the village.

What is the purpose of the text above?