code: def setUp(self):
      self.data = pd.DataFrame(
          {
              "x": [1, 2, 3],
              "y": [0, 3, 2],
              "e": [1, 1.5, 2],
          },
          columns=["x", "y", "e"],
      )
  
imports: from unittest import skip, skipIf
  import pandas
  import holoviews
  from holoviews.core.options import Cycle, Store
  from holoviews.element import ErrorBars, Points, Rectangles, Table, VSpan
  from holoviews.element.comparison import ComparisonTestCase
  from holoviews.plotting.util import linear_gradient
  from holoviews.selection import link_selections
  from holoviews.streams import SelectionXY
label_desc: Use image node_id 1 for calling the TestLinkSelections obj's underlying member method code with example usage: obj.setUp() without return types