code: def test_constrained_layout4():
      """Test constrained_layout for a single colorbar with subplots"""
  
      fig, axs = plt.subplots(2, 2, layout="constrained")
      for ax in axs.flat:
          pcm = example_pcolor(ax, fontsize=24)
      fig.colorbar(pcm, ax=axs, pad=0.01, shrink=0.6)
  
imports: import gc
  import numpy
  import pytest
  import matplotlib
  from matplotlib.testing.decorators import image_comparison
  import matplotlib.pyplot
  import matplotlib.transforms
  from matplotlib import gridspec, ticker
label_desc: Use image node_id 6 for calling a global function with example usage: test_constrained_layout4() without return types