code: def test_extend_range(self) -> None:
      with self.assertRaises(ValueError):
          extend_range(lower=1, upper=-1)
      self.assertEqual(extend_range(lower=-1, upper=1), (-1.2, 1.2))
      self.assertEqual(
          extend_range(lower=-1, upper=0, percent=30), (-1.3, 0.3)
      )
      self.assertEqual(
          extend_range(lower=0, upper=1, percent=50), (-0.5, 1.5)
      )
  
imports: from ax.plot.helper import arm_name_to_sort_key, extend_range
  from ax.utils.common.testutils import TestCase
label_desc: Use image node_id 1 for calling the HelperTest obj's underlying member method code with example usage: obj.test_extend_range() without return types