#includeIn this example, we create a QVBoxLayout object and set its margin to 10 pixels with `setMargin()`. We then add two QLabel widgets to the layout and set it to a QWidget. The result is a window with two labels arranged vertically and a margin of 10 pixels around them. The package library for QVBoxLayout is QtGui.#include // ... QVBoxLayout *layout = new QVBoxLayout(); // Set margin to 10 pixels layout->setMargin(10); // Add widgets to the layout layout->addWidget(new QLabel("Hello")); layout->addWidget(new QLabel("World")); // Set the layout to a widget QWidget *widget = new QWidget(); widget->setLayout(layout); // Show the widget widget->show();