code: def binned_pixelrange(self, waverange, **kwargs):
          
          x = units.validate_quantity(
              waverange, self._internal_wave_unit, equivalencies=u.spectral())
          return binning.pixel_range(self.binset.value, x.value, **kwargs)
docs: Calculate the number of pixels within the given wavelength
          range and `binset`.
  
          Parameters
          ----------
          waverange : tuple of float or `~astropy.units.quantity.Quantity`
              Lower and upper limits of the desired wavelength range.
              If not a Quantity, assumed to be in Angstrom.
  
          kwargs : dict
              Keywords accepted by :func:`synphot.binning.pixel_range`.
  
          Returns
          -------
          npix : int
              Number of pixels.