class_docstr: Test ops
code: def test_latest(self):
      op = ops.test_revision().latest()
      self.assertTrue(op.is_latest)
      self.assertEqual(op()[0], "main")
  
file_path: towhee/tests/unittests/runtime/test_factory.py
imports: import unittest
  from towhee.runtime import ops, register
label_desc: Use image node_id 3 for calling the TestOps obj's underlying member method code with example usage: obj.test_latest() without return types