'Get annotations for each cell of the heatmap with graph_objs.Annotation
:rtype (list[dict]) annotations: list of annotations for each cell of
the heatmap'

def make_annotations(self):

    (min_text_color, max_text_color) = _AnnotatedHeatmap.get_text_color(self)
    z_mid = _AnnotatedHeatmap.get_z_mid(self)
    annotations = []
    for (n, row) in enumerate(self.z):
        for (m, val) in enumerate(row):
            font_color = (min_text_color if (val < z_mid) else max_text_color)
            annotations.append(graph_objs.Annotation(text=str(self.annotation_text[n][m]), x=self.x[m], y=self.y[n], xref='x1', yref='y1', font=dict(color=font_color), showarrow=False))
    return annotations
