examples/research_projects/visual_bert/visualizing_image.py/SingleImageViz/add_box
class SingleImageViz:    def add_box(self, box, color=None):
        if color is None:
            color = self.edgecolor
        (x0, y0, x1, y1) = box
        width = x1 - x0
        height = y1 - y0
        self.ax.add_patch(
            mpl.patches.Rectangle(
                (x0, y0),
                width,
                height,
                fill=False,
                edgecolor=color,
                linewidth=self.font_size // 3,
                alpha=self.alpha,
                linestyle=self.linestyle,
            )
        )