def METHOD_NAME(self):
    """
    Compact (lower-level) JSON formatting of a Line3DBox.
    """
    # TODO: account for line widths and style
    color = self.edge_color.to_rgba()
    if len(color) < 4 and self.edge_opacity:
        color = color + [self.edge_opacity.opacity]
    data = convert_coord_collection(self.lines, "line", color)
    # print("### json Line3DBox", data)
    return data