code: def lbl(axis, label, size=22):
      
      at = AnchoredText(label, loc=2, prop=dict(size=size), frameon=True)
      at.patch.set_boxstyle("round,pad=0.,rounding_size=0.0")
      #bb = axis.get_yaxis_transform()
      #at = AnchoredText(label,
      #        loc=3, prop=dict(size=18), frameon=True,
      #        bbox_to_anchor=(-0.5,1),#(-.255, 0.90),
      #        bbox_transform=bb,#axis.transAxes
      #    )
      axis.add_artist(at)
docs: Put a figure label in an axis