code: def test_extended_dataclass_mixin():
      @dataclass
      class MyClass(py_datastructures.ExtendedDataClassMixin):
          int1: int
          str1: str
  
      assert MyClass.get_fields() == ["int1", "str1"]
  
file_path: jiant/tests/utils/python/test_datastructures.py
imports: import json
  import pytest
  from dataclasses import dataclass
  import jiant.utils.python.datastructures
label_desc: Use image node_id 7 for calling a global function with example usage: test_extended_dataclass_mixin() without return types