 User’s Guide section on
<a href="https://mc-stan.org/docs/stan-users-guide/posterior-prediction.html#stand-alone-generated-quantities-and-ongoing-prediction">Stand-alone generated quantities and ongoing prediction</a>.</p>
<p>This method requires sub-argument <code>fitted_params</code> which takes as its value
an existing Stan CSV file that contains a sample from an equivalent model,
i.e., a model with the same parameters, transformed parameters, and model blocks,
conditioned on the same data.</p>
<p>If 