code: def optimize_auto(self,max_iters=10000,verbose=True):
          
          self.Z.fix(warning=False)
          self.kern.fix(warning=False)
          self.kern_row.fix(warning=False)
          self.Zr.fix(warning=False)
          self.Xr.fix(warning=False)
          self.optimize(max_iters=int(0.1*max_iters),messages=verbose)
          self.unfix()
          self.optimize(max_iters=max_iters,messages=verbose)
docs: Optimize the model parameters through a pre-defined protocol.
  
          :param int max_iters: the maximum number of iterations.
          :param boolean verbose: print the progress of optimization or not.