UNTESTED.
        Should return a boolean array representing the pixels in the footprint.

def footprint(self, nside=None):
        """
        UNTESTED.
        Should return a boolean array representing the pixels in the footprint.
        """
        if nside is None:
            nside = self.nside_pixel
        elif nside < self.nside_catalog: 
            raise Exception('Requested nside=%i is less than catalog_nside'%nside)
        elif nside > self.nside_pixel:
            raise Exception('Requested nside=%i is greater than pixel_nside'%nside)
        pix = np.arange(hp.nside2npix(nside), dtype=int)
        map = self.inFootprint(pix,nside)
        return map