def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def _ui_font_style(layout, font_style):

        split = layout.split()

        col = split.column()
        col.label(text="Kerning Style:")
        col.row().prop(font_style, "font_kerning_style", expand=True)
        col.prop(font_style, "points")

        col = split.column()
        col.label(text="Shadow Offset:")
        col.prop(font_style, "shadow_offset_x", text="X")
        col.prop(font_style, "shadow_offset_y", text="Y")

        col = split.column()
        col.prop(font_style, "shadow")
        col.prop(font_style, "shadow_alpha")
        col.prop(font_style, "shadow_value")

        layout.separator()