code: def calc_stress_tf(self, lin, lout, damped):
          
          tf = self.calc_strain_tf(lin, lout)
          if damped:
              # Scale by complex shear modulus to include the influence of
              # damping
              tf *= lout.layer.comp_shear_mod
          else:
              tf *= lout.layer.shear_mod
  
          return tf
docs: Compute the stress transfer function.
  
          Parameters
          ----------
          lin : :class:`~site.Location`
              Location of input
          lout : :class:`~site.Location`
              Location of output. Note that this would typically be midheight
              of the layer.