def annotation_heatmap(self, canvas, X, annotation, extent, label=None, **kwargs):
raise NotImplementedError("<STR_LIT>")<EOL>
Plot an annotation heatmap. That is like an imshow, but
put the text of the annotation inside the cells of the heatmap (centered).

:param canvas: the canvas to plot on
:param array-like annotation: the annotation labels for the heatmap
:param [horizontal_min,horizontal_max,vertical_min,vertical_max] extent: the extent of where to place the heatmap
:param str label: the label for the heatmap
:return: a list of both the heatmap and annotation plots [heatmap, annotation], or the interactive update object (alone)