code: def setUp(self):
      super().setUp()
  
      # Build Dash app mock
      self.app = MagicMock()
      self.decorator = MagicMock()
      self.app.callback.return_value = self.decorator
  
file_path: holoviews/holoviews/tests/plotting/plotly/test_dash.py
imports: import unittest
  from unittest.mock import MagicMock, patch
  from dash._callback_context import CallbackContext
  from holoviews import Bounds, DynamicMap, Scatter
  from holoviews.plotting.plotly.dash import DashComponents, decode_store_data, encode_store_data, to_dash
  from holoviews.streams import BoundsXY, RangeXY, Selection1D
  from .test_plot import TestPlotlyPlot
  import plotly.io
label_desc: Use image node_id 1 for calling the TestHoloViewsDash obj's underlying member method code with example usage: obj.setUp() without return types