def add_image(self, filename, *, width=NoEscape(r'0.8\textwidth'),
                  placement=NoEscape(r'\centering')):
        """Add an image to the figure.

        Args
        ----
        filename: str
            Filename of the image.
        width: str
            The width of the image
        placement: str
            Placement of the figure, `None` is also accepted.

        """

        if width is not None:
            if self.escape:
                width = escape_latex(width)

            width = 'width=' + str(width)

        if placement is not None:
            self.append(placement)

        self.append(StandAloneGraphic(image_options=width,
                                      filename=fix_filename(filename)))
Add an image to the figure.

        Args
        ----
        filename: str
            Filename of the image.
        width: str
            The width of the image
        placement: str
            Placement of the figure, `None` is also accepted.