class_docstr: This layout engine does not adjust the figure layout at all.
  
  The purpose of this `.LayoutEngine` is to act as a placeholder when the user removes
  a layout engine to ensure an incompatible `.LayoutEngine` cannot be set later.
  
  Parameters
  ----------
  adjust_compatible, colorbar_gridspec : bool
      Allow the PlaceHolderLayoutEngine to mirror the behavior of whatever
      layout engine it is replacing.
code: def __init__(self, adjust_compatible, colorbar_gridspec, **kwargs):
      self._adjust_compatible = adjust_compatible
      self._colorbar_gridspec = colorbar_gridspec
      super().__init__(**kwargs)
  
imports: from contextlib import nullcontext
  import matplotlib
  from matplotlib._constrained_layout import do_constrained_layout
  from matplotlib._tight_layout import get_subplotspec_list, get_tight_layout_figure
label_desc: Use image node_id 1 to create a new PlaceHolderLayoutEngine object from inherited base classes: LayoutEngine with example: obj = PlaceHolderLayoutEngine(adjust_compatible, colorbar_gridspec)