code: def test_constructor(self):
      self.assertEqual(self._empty_mapping(), self._empty_mapping())
  
imports: import unittest
  import collections
  from test.support import Py_C_RECURSION_LIMIT
label_desc: Use image node_id 7 for calling the BasicTestMappingProtocol obj's underlying member method code with example usage: obj.test_constructor() without return types