@@ -85,6 +85,11 @@ def do_constrained_layout(fig, renderer, h_pad, w_pad,
        A value of 0.2 for a three-column layout would have a space
        of 0.1 of the figure width between each column.
        If h/wspace < h/w_pad, then the pads are used instead.
+
+    Returns
+    -------
+    layoutgrid : private debugging structure
+        layoutgrid: useful for debugging.
     """
 
     # make layoutgrid tree...
@@ -125,6 +130,7 @@ def do_constrained_layout(fig, renderer, h_pad, w_pad,
                                'axes sizes collapsed to zero.  Try making '
                                'figure larger or axes decorations smaller.')
         _reset_margins(_layoutgrids, fig)
+    return _layoutgrids
 
 
 def _make_layoutgrids(fig, _layoutgrids):
 
@@ -22,7 +22,6 @@
 import numpy as np
 from matplotlib.transforms import Bbox
 
-
 _log = logging.getLogger(__name__)
 
 
@@ -508,13 +507,14 @@ def print_children(lb):
         print_children(child)
 
 
-def plot_children(fig, lg, level=0, printit=False):
+def plot_children(fig, lg=None, level=0, printit=False):
     """Simple plotting to show where boxes are."""
     import matplotlib.pyplot as plt
     import matplotlib.patches as mpatches
 
-    fig.canvas.draw()
-
+    if lg is None:
+        _layoutgrids = fig.execute_constrained_layout()
+        lg = _layoutgrids[fig]
     colors = plt.rcParams["axes.prop_cycle"].by_key()["color"]
     col = colors[level]
     for i in range(lg.nrows):
 
@@ -2989,6 +2989,10 @@ def execute_constrained_layout(self, renderer=None):
         Use ``layoutgrid`` to determine pos positions within Axes.
 
         See also `.set_constrained_layout_pads`.
+
+        Returns
+        -------
+        layoutgrid : private debugging object
         """
 
         from matplotlib._constrained_layout import do_constrained_layout
@@ -3002,7 +3006,8 @@ def execute_constrained_layout(self, renderer=None):
         h_pad = h_pad / height
         if renderer is None:
             renderer = _get_renderer(fig)
-        do_constrained_layout(fig, renderer, h_pad, w_pad, hspace, wspace)
+        return do_constrained_layout(fig, renderer, h_pad, w_pad,
+                                     hspace, wspace)
 
     def tight_layout(self, *, pad=1.08, h_pad=None, w_pad=None, rect=None):
         """
 
@@ -71,7 +71,6 @@ def example_plot(ax, fontsize=12, hide_labels=False):
         ax.set_ylabel('y-label', fontsize=fontsize)
         ax.set_title('Title', fontsize=fontsize)
 
-
 fig, ax = plt.subplots(constrained_layout=False)
 example_plot(ax, fontsize=24)
 
@@ -508,6 +507,7 @@ def docomplicated(suptitle=None):
 example_plot(ax3)
 example_plot(ax4)
 fig.suptitle('subplot2grid')
+plt.show()
 
 ###############################################################################
 # Other Caveats
@@ -588,7 +588,7 @@ def docomplicated(suptitle=None):
 
 fig, ax = plt.subplots(constrained_layout=True)
 example_plot(ax, fontsize=24)
-plot_children(fig, fig._layoutgrid)
+plot_children(fig)
 
 #######################################################################
 # Simple case: two Axes
@@ -603,7 +603,7 @@ def docomplicated(suptitle=None):
 fig, ax = plt.subplots(1, 2, constrained_layout=True)
 example_plot(ax[0], fontsize=32)
 example_plot(ax[1], fontsize=8)
-plot_children(fig, fig._layoutgrid, printit=False)
+plot_children(fig, printit=False)
 
 #######################################################################
 # Two Axes and colorbar
@@ -616,7 +616,7 @@ def docomplicated(suptitle=None):
 im = ax[0].pcolormesh(arr, **pc_kwargs)
 fig.colorbar(im, ax=ax[0], shrink=0.6)
 im = ax[1].pcolormesh(arr, **pc_kwargs)
-plot_children(fig, fig._layoutgrid)
+plot_children(fig)
 
 #######################################################################
 # Colorbar associated with a Gridspec
@@ -629,7 +629,7 @@ def docomplicated(suptitle=None):
 for ax in axs.flat:
     im = ax.pcolormesh(arr, **pc_kwargs)
 fig.colorbar(im, ax=axs, shrink=0.6)
-plot_children(fig, fig._layoutgrid, printit=False)
+plot_children(fig, printit=False)
 
 #######################################################################
 # Uneven sized Axes
@@ -654,7 +654,7 @@ def docomplicated(suptitle=None):
 im = ax.pcolormesh(arr, **pc_kwargs)
 ax = fig.add_subplot(gs[1, 1])
 im = ax.pcolormesh(arr, **pc_kwargs)
-plot_children(fig, fig._layoutgrid, printit=False)
+plot_children(fig, printit=False)
 
 #######################################################################
 # One case that requires finessing is if margins do not have any artists
@@ -669,4 +669,5 @@ def docomplicated(suptitle=None):
 ax01 = fig.add_subplot(gs[0, 2:])
 ax10 = fig.add_subplot(gs[1, 1:3])
 example_plot(ax10, fontsize=14)
-plot_children(fig, fig._layoutgrid)
+plot_children(fig)
+plt.show()