code: def test_function_delete(self, r):
      r.function_load(f"#!{engine} name={lib} \n {set_function}")
      with pytest.raises(ResponseError):
          r.function_load(f"#!{engine} name={lib} \n {set_function}")
      assert r.fcall("set", 1, "foo", "bar") == b"OK"
      assert r.function_delete("mylib")
      with pytest.raises(ResponseError):
          r.fcall("set", 1, "foo", "bar")
  
file_path: redis-py/tests/test_function.py
imports: import pytest
  from redis.exceptions import ResponseError
  from .conftest import assert_resp_response, skip_if_server_version_lt
label_desc: Use image node_id 3 for calling the TestFunction obj's underlying member method code with example usage: obj.test_function_delete(r) without return types