code: def add_test_case(self, name, test_func):
      if not name.startswith("test_"):
          raise ValueError(
              "Test name must start with test_: {}".format(name)
          )
      if hasattr(self, name):
          raise ValueError("Duplicated test name: {}".format(name))
      setattr(self, name, test_func)
  
imports: import unittest
  import numpy
label_desc: Use image node_id 3 for calling the TestCase obj's underlying member method code with example usage: obj.add_test_case(name, test_func) without return types