docs: def load_spectrum_fits_messed_x(filename, sp_ref=None):
      """Loads FITS file spectrum that does not have the proper headers. Returns a Spectrum"""
      import f311.filetypes as ft
  
      # First tries to load as usual
      f = load_with_classes(filename, (ft.FileSpectrumFits,))
  
      if f is not None:
          ret = f.spectrum
      else:
          hdul = fits.open(filename)
  
          hdu = hdul[0]
          if not hdu.header.get("CDELT1"):
              hdu.header["CDELT1"] = 1 if sp_ref is None else sp_ref.delta_lambda
          if not hdu.header.get("CRVAL1"):
              hdu.header["CRVAL1"] = 0 if sp_ref is None else sp_ref.x[0]
  
          ret = ft.Spectrum()
          ret.from_hdu(hdu)
          ret.filename = filename
          original_shape = ret.y.shape  # Shape of data before squeeze
          # Squeezes to make data of shape e.g. (1, 1, 122) into (122,)
          ret.y = ret.y.squeeze()
  
          if len(ret.y.shape) > 1:
              raise RuntimeError(
                  "Data contains more than 1 dimension (shape is {0!s}), "
                  "FITS file is not single spectrum".format(original_shape))
  
      return ret