 which will be pass
the viewId of Google Analytics property to fetch data from.</li>
<li>
<code>model_f</code> - A function to work with the data you have
fetched. The first argument should be the data.frame that is produced by
the data fetching function, <code>data_f()</code>.</li>
<li>
<code>output_f</code> - A function to plot the data. The first
argument should be the data.frame that is produced by the model
function, <code>model_f()</code>.</li>
<li>All functions you create must include <code>...</code