docs: def run(self, scale_out, sectors='all'):
          """Evolve the Wilson coefficients to the scale `scale_out`.
  
          Parameters:
  
          - scale_out: output scale
          - sectors: optional. If provided, must be a tuple of strings
            corresponding to WCxf sector names. Only Wilson coefficients
            belonging to these sectors will be present in the output.
  
          Returns an instance of `wcxf.WC`.
          """
          C_out = self._run_dict(scale_out, sectors=sectors)
          all_wcs = set(wcxf.Basis[self.eft, 'JMS'].all_wcs)  # to speed up lookup
          C_out = {k: v for k, v in C_out.items()
                   if v != 0 and k in all_wcs}
          return wcxf.WC(eft=self.eft, basis='JMS',
                         scale=scale_out,
                         values=wcxf.WC.dict2values(C_out))