code: def test_register(self):
      registry = formats.get_registry()
      assert_false(CustomFormat in registry.values())
  
      formats.register("trt", CustomFormat)
  
      assert_true(CustomFormat in registry.values())
      assert_true("trt" in registry.keys())
  
imports: import os
  import unittest
  from nose.tools import *
  from textblob import formats
  from textblob.compat import unicode
label_desc: Use image node_id 2 for calling the TestRegistry obj's underlying member method code with example usage: obj.test_register() without return types