class_docstr: Utility renderer using Matplotlib to render a grid of plots over the same (x, y) range.
  
  Args:
      nrows (int, optional): Number of rows of plots, default ``1``.
      ncols (int, optional): Number of columns of plots, default ``1``.
      figsize (tuple(float, float), optional): Figure size in inches, default ``(9, 9)``.
      show_frame (bool, optional): Whether to show frame and axes ticks, default ``True``.
      backend (str, optional): Matplotlib backend to use or ``None`` for default backend.
          Default ``None``.
      gridspec_kw (dict, optional): Gridspec keyword arguments to pass to ``plt.subplots``,
          default None.
docstr: Save plots to an ``io.BytesIO`` buffer.
  
  Return:
      BytesIO: PNG image buffer.
code: def save_to_buffer(self) -> io.BytesIO:
      """Save plots to an ``io.BytesIO`` buffer.
  
      Return:
          BytesIO: PNG image buffer.
      """
      self._autoscale()
      buf = io.BytesIO()
      self._fig.savefig(buf, format="png")
      buf.seek(0)
      return buf
  
imports: from __future__ import annotations
  from collections.abc import Sequence
  import io
  from typing import TYPE_CHECKING, Any, cast
  import matplotlib.collections
  import matplotlib.pyplot
  import numpy
  from contourpy import FillType, LineType
  from contourpy.convert import convert_filled, convert_lines
  from contourpy.enum_util import as_fill_type, as_line_type
  from contourpy.util.mpl_util import filled_to_mpl_paths, lines_to_mpl_paths
  from contourpy.util.renderer import Renderer
label_desc: Use image node_id 10 for calling the MplRenderer obj's underlying member method code with example usage: obj.save_to_buffer() and returns: buf