code: def plot(self, wavelengths=None, **kwargs):  # pragma: no cover
          
          w, y = self._get_arrays(wavelengths)
          self._do_plot(w, y, **kwargs)
docs: Plot the spectrum.
  
          .. note:: Uses ``matplotlib``.
  
          Parameters
          ----------
          wavelengths : array-like, `~astropy.units.quantity.Quantity`, or `None`
              Wavelength values for sampling.
              If not a Quantity, assumed to be in Angstrom.
              If `None`, `waveset` is used.
  
          title : str
              Plot title.
  
          xlog, ylog : bool
              Plot X and Y axes, respectively, in log scale.
              Default is linear scale.
  
          left, right : `None` or number
              Minimum and maximum wavelengths to plot.
              If `None`, uses the whole range. If a number is given,
              must be in Angstrom.
  
          bottom, top : `None` or number
              Minimum and maximum flux/throughput to plot.
              If `None`, uses the whole range. If a number is given,
              must be in internal unit.
  
          save_as : str
              Save the plot to an image file. The file type is
              automatically determined by given file extension.
  
          Raises
          ------
          synphot.exceptions.SynphotError
              Invalid inputs.