old_contents: import unittest
  from twelve_tone.composer import Composer
  
  
  class TestMatrix(unittest.TestCase):
  
      def test_top_row(self):
          m = Composer().compose()
          # check top row is unique
          duplicate_val = False
          if len(m[0]) > len(set(m[0])):
              duplicate_val = True
          self.assertFalse(duplicate_val)
          self.assertEquals(len(m[0]), 12)
  
      def test_transform_cell(self):
          negative = -3
          transformed_num = Composer()._transform_cell(negative)
          self.assertEqual(transformed_num, 9)
  
      def test_translate_pitch(self):
          cell = 3
          pitch = Composer().get_pitch(cell)
          self.assertEqual(pitch, 'D')
  
      def test_master(self):
          row = [3, 1, 9, 5, 4, 6, 8, 7, 12, 10, 11, 2]
          m = Composer().compose(top_row=row)
          self.assertEqual(m[0][0], 3)
          self.assertEqual(m[11][0], 4)
          self.assertEqual(m[0][11], 2)
          self.assertEqual(m[11][11], 3)
          # check for 3s all the way diagonal
          for x in range(0, 12):
              self.assertEqual(m[x][x], 3)
  
new_contents: import unittest
  
  from twelve_tone.composer import Composer
  
  
  class TestMatrix(unittest.TestCase):
  
      def test_top_row(self):
          m = Composer().compose()
          # check top row is unique
          duplicate_val = False
          if len(m[0]) > len(set(m[0])):
              duplicate_val = True
          self.assertFalse(duplicate_val)
          self.assertEquals(len(m[0]), 12)
  
      def test_transform_cell(self):
          negative = -3
          transformed_num = Composer()._transform_cell(negative)
          self.assertEqual(transformed_num, 9)
  
      def test_translate_pitch(self):
          cell = 3
          pitch = Composer().get_pitch(cell)
          self.assertEqual(pitch, 'D')
  
      def test_master(self):
          row = [3, 1, 9, 5, 4, 6, 8, 7, 12, 10, 11, 2]
          m = Composer().compose(top_row=row)
          self.assertEqual(m[0][0], 3)
          self.assertEqual(m[11][0], 4)
          self.assertEqual(m[0][11], 2)
          self.assertEqual(m[11][11], 3)
          # check for 3s all the way diagonal
          for x in range(0, 12):
              self.assertEqual(m[x][x], 3)
  
subject: fix isort import format