pper left', 'upper center', 'upper right',
            'center left', 'center', 'center right',
            'lower left', 'lower center', 'lower right'.
            For backward compatibility, numeric values are accepted as well.
            See the parameter *loc* of `.Legend` for details.
        pad : float, default: 0.1
            Padding around the label and size bar, in fraction of the font
            size.
        borderpad : float, default: 0.1
            Border padding, in fraction of the font size.
        sep : float, default: 2
            Separation between the label and the size bar, in points.
        frameon : bool, default: True
            If True, draw a box around the horizontal bar and label.
        size_vertical : float, default: 0
            Vertical length of the size bar, given in coordinates of
            *transform*.
        color : str, default: 'black'
            Color for the size bar and label.
        label_top : bool, default: False
            If True, the label will be over the size bar.
        fontproperties : `~matplotlib.font_manager.FontProperties`, optional
            Font properties for the label text.
        fill_bar : bool, optional
            If True and if *size_vertical* is nonzero, the size bar will
            be filled in with the color specified by the size bar.
            Defaults to True if *size_vertical* is greater than
            zero and False otherwise.
        **kwargs
            Keyword arguments forwarded to `.AnchoredOffsetbox`.

        Attributes
        ----------
        size_bar : `~matplotlib.offsetbox.AuxTransformBox`
            Container for the size bar.
        txt_label : `~matplotlib.offsetbox.TextArea`
            Container for the label of the size bar.

        Notes
        -----
        If *prop* is passed as a keyword argument, but *fontproperties* is
        not, then *prop* is assumed to be the intended *fontproperties*.
        Using both *prop* and *fontproperties* is not supported.

        Examples
        --------
        >>> import matplotlib.pyplot as plt
        >>> import numpy as np
        >>> from mpl_toolkits.axes_grid1.anchored_artists import (
        ...     AnchoredSizeBar)
        >>> fig, ax = plt.subplots()
        >>> ax.imshow(np.random.random((10, 10)))
        >>> bar = AnchoredSizeBar(ax.transData, 3, '3 data units', 4)
        >>> ax.add_artist(bar)
        >>> fig.show()

        Using all the optional parameters

        >>> import matplotlib.font_manager as fm
        >>> fontprops = fm.FontProperties(size=14, family='monospace')
        >>> bar = AnchoredSizeBar(ax.transData, 3, '3 units', 4, pad=0.5,
        ...                       sep=5, borderpad=0.5, frameon=False,
        ...                       size_vertical=0.5, color='white',
        ...                       fontproperties=fontprops)
        Nr