code: def test_NameOrShortSignature(self) -> None:
      arm = Arm(parameters={"y": 0.25, "x": 0.75, "z": 75}, name="0_0")
      self.assertEqual(arm.name_or_short_signature, "0_0")
  
      arm = Arm(parameters={"y": 0.25, "x": 0.75, "z": 75})
      self.assertEqual(arm.name_or_short_signature, arm.signature[-8:])
  
file_path: Ax/ax/core/tests/test_arm.py
imports: from ax.core.arm import Arm
  from ax.utils.common.testutils import TestCase
label_desc: Use image node_id 4 for calling the ArmTest obj's underlying member method code with example usage: obj.test_NameOrShortSignature() without return types