le is <code>GRangesList</code>.</p>
<p>These looks like standard <code>list</code>s from base R, but they require that every element of the list is of the same class. This is convenient from a data structure perspective; we know exactly what is in the list.</p>
<p>But things are also happening behind the scenes. These types of lists often have additional compression build into them. Because of this, it is best to use specific methods/functions on them, as opposed to the standard toolbox of <code>sapply</cod