public function getClassByFQSEN(FullyQualifiedClassName $fqsen) : Clazz
{
$clazz = $this->fqsen_class_map[$fqsen];
// This is an optimization that saves us a few minutes
// on very large code bases.
//
// Instead of 'hydrating' all classes (expanding their
// types and importing parent methods, properties, etc.)
// all in one go, we just do it on the fly as they're
// requested. When running as multiple processes this
// lets us avoid a significant amount of hydration per
// process.
if ($this->should_hydrate_requested_elements) {
$clazz->hydrate($this);
}
return $clazz;
}