code: def _update_param(self):
          r
  
          # Update relaxation parameter.
          if not isinstance(self._rho_update, type(None)):
              self._rho = self._rho_update(self._rho)
  
          # Update proximal dual parameter.
          if not isinstance(self._sigma_update, type(None)):
              self._sigma = self._sigma_update(self._sigma)
  
          # Update proximal primal parameter.
          if not isinstance(self._tau_update, type(None)):
              self._tau = self._tau_update(self._tau)
docs: r"""Update parameters
  
          This method updates the values of the algorthm parameters with the
          methods provided