code: def test_labels_plot(self):
      text = Labels([(0, 0, "Test")])
      plot = bokeh_renderer.get_plot(text)
      source = plot.handles["source"]
      data = {"x": np.array([0]), "y": np.array([0]), "Label": ["Test"]}
      for c, col in source.data.items():
          self.assertEqual(col, data[c])
  
imports: import unittest
  import numpy
  import holoviews
  from holoviews.element import Arrow, HLine, HLines, HSpan, HSpans, Labels, Slope, Text, VLine, VLines, VSpan, VSpans
  from holoviews.plotting.bokeh.util import bokeh32, bokeh33
  from .test_plot import TestBokehPlot, bokeh_renderer
label_desc: Use image node_id 1 for calling the TestLabelsPlot obj's underlying member method code with example usage: obj.test_labels_plot() without return types