code: def test_widget_client_update(self, rename_libraries):
      import perspective
  
      assert perspective.is_libpsp() is False
      data = {"a": np.arange(0, 50)}
      comparison_data = {"a": [i for i in range(50)]}
      widget = perspective.PerspectiveWidget(data)
      mocked_post = partial(
          mock_post,
          assert_msg={"cmd": "update", "data": comparison_data},
      )
      widget.post = MethodType(mocked_post, widget)
      widget.update(data)
      assert hasattr(widget, "table") is False
  
imports: import os
  import pytest
  import sys
  import numpy
  import pandas
  from datetime import date, datetime
  from functools import partial
  from types import MethodType
label_desc: Use image node_id 21 for calling the TestClient obj's underlying member method code with example usage: obj.test_widget_client_update(rename_libraries) without return types