docs: def _run_sm_scale_in(self, C_out, scale_sm=91.1876):
          """Get the SM parameters at the EW scale, using an estimate `C_out`
          of the Wilson coefficients at that scale, and run them to the
          input scale."""
          # initialize an empty SMEFT instance
          smeft_sm = SMEFT()
          C_in_sm = beta.C_array2dict(np.zeros(9999))
          # set the SM parameters to the values obtained from smpar.smeftpar
          C_SM = smpar.smeftpar(scale_sm, self.scale_high, C_out, basis='Warsaw')
          C_SM = {k: v for k, v in C_SM.items() if k in definitions.SM_keys}
          # set the Wilson coefficients at the EW scale to C_out
          C_in_sm.update(C_out)
          C_in_sm.update(C_SM)
          smeft_sm.set_initial(C_in_sm, scale_sm, scale_high=self.scale_high)
          # run up (with 1% relative precision, ignore running of Wilson coefficients)
          C_SM_high = smeft_sm.rgevolve(self.scale_in, newphys=False, rtol=0.01, atol=1)
          return {k: v for k, v in C_SM_high.items() if k in definitions.SM_keys}