code: def test_adjointlayout_single(self):
      layout = AdjointLayout([self.view1])
      self.assertEqual(layout.main, self.view1)
  
imports: import numpy
  import pytest
  from holoviews import AdjointLayout, Element, GridSpace, HoloMap, Layout, NdLayout, Overlay
  from holoviews.element import Curve, HLine, Image
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 1 for calling the AdjointLayoutTest obj's underlying member method code with example usage: obj.test_adjointlayout_single() without return types