def test_is_negative_ordinary_progression(self):
     self.assertEqual(
         -1,
         arithmetic_progression.arith_geo([-1, -8, -27, -64, -125]),
         msg='should return -1 for [-1, -8, -27, -64, -125]'
     )
 def test_is_positive_ordinary_progression_one(self):
     self.assertEqual(-1,
                      arithmetic_progression.arith_geo([1, 2, 3, 5, 8]),
                      msg='should return -1 for [1, 2, 3, 5, 8]'
                      )
 def test_is_positive_ordinary_progression_two(self):
     self.assertEqual(-1,
                      arithmetic_progression.arith_geo([1, 3, 6, 10, 15]),
                      msg='should return -1 for [1, 3, 6, 10, 15]'
                      )
 def test_is_negative_geometric_progression_two(self):
     self.assertEqual(
         'Geometric',
         arithmetic_progression.arith_geo([-128, 64, -32, 16, -8]),
         msg='should return `Geometric` for [-128, 64, -32, 16, -8]'
     )
 def test_empty_list(self):
     self.assertEqual(0, arithmetic_progression.arith_geo([]),
                      msg='should return 0 for an empty array')
 def test_is_positive_geometric_progression_two(self):
     self.assertEqual(
         'Geometric',
         arithmetic_progression.arith_geo([0.5, 3.5, 24.5, 171.5]),
         msg='should return `Geometric` for [0.5, 3.5, 24.5, 171.5]'
     )
 def test_is_positive_geometric_progression_one(self):
     self.assertEqual(
         'Geometric',
         arithmetic_progression.arith_geo([2, 6, 18, 54, 162]),
         msg='should return `Geometric` for [2, 6, 18, 54, 162]'
     )
 def test_is_negative_arithematic_progression(self):
     self.assertEqual(
         'Arithmetic',
         arithmetic_progression.arith_geo([15, 10, 5, 0, -5, -10]),
         msg='should return `Arithmetic` for [15, 10, 5, 0, -5, -10]'
     )
 def test_is_positive_arithematic_progression_two(self):
     self.assertEqual(
         'Arithmetic',
         arithmetic_progression.arith_geo([5, 11, 17, 23, 29, 35, 41]),
         msg='should return `Arithmetic` for [5, 11, 17, 23, 29, 35, 41]'
     )
 def test_is_positive_arithematic_progression_one(self):
     self.assertEqual(
         'Arithmetic', arithmetic_progression.arith_geo([2, 4, 6, 8, 10]),
         msg='should return `Arithmetic` for [2, 4, 6, 8, 10]')