HDU list (`~astropy.io.fits.HDUList`).

        Different pieces collected together in a HDU list.

        This method makes it easy to write the example dataset to a FITS
        file with multiple HDUs.

def hdu_list(self):
        """HDU list (`~astropy.io.fits.HDUList`).

        Different pieces collected together in a HDU list.

        This method makes it easy to write the example dataset to a FITS
        file with multiple HDUs.
        """
        hdu_list = fits.HDUList()

        hdu = _table_to_bintable(self.source_table)
        hdu.name = 'sources'
        hdu_list.append(hdu)

        hdu = _table_to_bintable(self.event_table)
        hdu.name = 'events'
        hdu_list.append(hdu)

        hdu = self.image
        hdu.name = 'image'
        hdu_list.append(hdu)

        return hdu_list