code: def draw_text(ax):
      """Draw a text-box anchored to the upper-left corner of the figure."""
      box = AnchoredOffsetbox(
          child=TextArea("Figure 1a"), loc="upper left", frameon=True
      )
      box.patch.set_boxstyle("round,pad=0.,rounding_size=0.2")
      ax.add_artist(box)
  
file_path: matplotlib/galleries/examples/misc/anchored_artists.py
imports: from matplotlib import pyplot
  from matplotlib.lines import Line2D
  from matplotlib.offsetbox import AnchoredOffsetbox, AuxTransformBox, DrawingArea, TextArea, VPacker
  from matplotlib.patches import Circle, Ellipse
label_desc: Use image node_id 1 for calling a global function with example usage: draw_text(ax) without return types