docs: def default_cy(self):
          """
          Native height of this image, calculated from its height in pixels and
          vertical dots per inch (dpi).
          """
          px_height = self.image.px_height
          horz_dpi = self.image.horz_dpi
          height_in_emu = 914400 * px_height / horz_dpi
          return Emu(height_in_emu)