A setter for the wavelength units

        Parameters
        ----------
        units: str, astropy.units.core.PrefixUnit
            The wavelength units

def wave_units(self, units):
        """
        A setter for the wavelength units

        Parameters
        ----------
        units: str, astropy.units.core.PrefixUnit
            The wavelength units
        """
        # Make sure it's length units
        if not units.is_equivalent(q.m):
            raise ValueError(units, ": New wavelength units must be a length.")

        # Update the units
        self._wave_units = units

        # Update all the wavelength values
        self._wave = self.wave.to(self.wave_units).round(5)
        self.wave_min = self.wave_min.to(self.wave_units).round(5)
        self.wave_max = self.wave_max.to(self.wave_units).round(5)
        self.wave_eff = self.wave_eff.to(self.wave_units).round(5)
        self.wave_center = self.wave_center.to(self.wave_units).round(5)
        self.wave_mean = self.wave_mean.to(self.wave_units).round(5)
        self.wave_peak = self.wave_peak.to(self.wave_units).round(5)
        self.wave_phot = self.wave_phot.to(self.wave_units).round(5)
        self.wave_pivot = self.wave_pivot.to(self.wave_units).round(5)
        self.width_eff = self.width_eff.to(self.wave_units).round(5)
        self.fwhm = self.fwhm.to(self.wave_units).round(5)