ends</span>
<span class='co'>## different covariance structures of the random effects</span>
<span class='co'>## and different number of classes</span>
<span class='va'>tuneGrid</span> <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/expand.grid.html'>expand.grid</a></span><span class='op'>(</span>
  dv <span class='op'>=</span> <span class='st'>"y"</span>,
  timevars <span class='op'>=</span> <span class='fu'><a href='https://rdrr.io/r/base/list.html'>list</a></span><span clas