class_docstr: Subplots figure specification.
  
  See: `gggrid()`
code: def as_dict(self):
      d = super().as_dict()
      d["kind"] = self.kind
      d["layout"] = self.__layout.as_dict()
      d["figures"] = [
          figure.as_dict() if figure is not None else None
          for figure in self.__figures
      ]
  
      return d
  
imports: from typing import Dict
  from lets_plot.plot.core import DummySpec
  from lets_plot.plot.core import FeatureSpec
  from lets_plot.plot.core import FeatureSpecArray
  from lets_plot.plot.core import _specs_to_dict
  from lets_plot.plot.core import _theme_dicts_merge
  from lets_plot.plot.core import _to_svg, _to_html, _export_as_raster
label_desc: Use image node_id 4 for calling the SupPlotsSpec obj's underlying member method code with example usage: obj.as_dict() and returns: d