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++ // Copyright (C) 2016 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ //! [0]
++ QDesignerPropertySheetExtension *propertySheet;
++ QExtensionManager manager = formEditor->extensionManager();
++
++ propertySheet = qt_extension<QDesignerPropertySheetExtension*>(manager, widget);
++
++ if(propertySheet) {...}
++ //! [0]
++
++
++ //! [1]
++ Q_DECLARE_EXTENSION_INTERFACE(MyExtension, "com.mycompany.myproduct.myextension")
++ //! [1]
++
++