code: def psf_class(self):
          
          if self._psf_type == 'GAUSSIAN':
              psf_type = "GAUSSIAN"
              fwhm = self._seeing
              kwargs_psf = {'psf_type': psf_type, 'fwhm': fwhm}
          elif self._psf_type == 'PIXEL':
              if self._psf_model is not None:
                  kwargs_psf = {'psf_type': "PIXEL", 'kernel_point_source': self._psf_model}
              else:
                  raise ValueError("You need to create the class instance with a psf_model!")
          else:
              raise ValueError("psf_type %s not supported!" % self._psf_type)
          psf_class = PSF(kwargs_psf)
          return psf_class
docs: creates instance of PSF() class based on knowledge of the observations
          For the full possibility of how to create such an instance, see the PSF() class documentation
  
          :return: instance of PSF() class