| QGIS API Documentation
    3.18.1-Zürich (202f1bf7e5)
    | 
#include <QHBoxLayout>#include "qgsprojectionselectionwidget.h"#include "qgsapplication.h"#include "qgsprojectionselectiondialog.h"#include "qgsproject.h"#include "qgssettings.h"#include "qgshighlightablecombobox.h"#include "qgscoordinatereferencesystemregistry.h"