def test_triplets():
    assert (DNA('AAA').split_DNA_triplets == ['AAA'])
    assert (DNA('AAATTTGGG').split_DNA_triplets == ['AAA', 'TTT', 'GGG'])
    assert (DNA('AAAT').split_DNA_triplets == ['AAA', 'T'])
def test_triplets():
    assert (DNA('AAA').split_DNA_triplets == ['AAA'])
    assert (DNA('AAATTTGGG').split_DNA_triplets == ['AAA', 'TTT', 'GGG'])
    assert (DNA('AAAT').split_DNA_triplets == ['AAA', 'T'])