def createComposition(self):
        '''
        Create a print Layout
        '''
        c = QgsPrintLayout(self.mProject)
        c.initializeDefaults()
        c.setUnits(QgsUnitTypes.LayoutMillimeters)

        g=QgsLayoutGridSettings(c)
        g.setOffset( QgsLayoutPoint(3.5, 0, QgsUnitTypes.LayoutMillimeters)   )
        g.setResolution( QgsLayoutMeasurement(2.5) )

        # Set page number
        self.getPageNumberNeeded()
        # Set main properties
        for i in range(1, self.numPages):
            p=QgsLayoutItemPage(c)
            #page.setPageSize('A6')
            p.setPageSize( QgsLayoutSize(self.pageWidth, self.pageHeight, QgsUnitTypes.LayoutMillimeters) )
            c.pageCollection().addPage(p)

        # Set the global currentComposition
        self.currentComposition = c

    def testReadWriteXml(self):
        p = QgsProject()
        l = QgsLayout(p)
        s = QgsLayoutGridSettings(l)
        s.setResolution(QgsLayoutMeasurement(5, QgsUnitTypes.LayoutPoints))
        s.setOffset(QgsLayoutPoint(6, 7, QgsUnitTypes.LayoutPixels))

        doc = QDomDocument("testdoc")
        elem = doc.createElement("test")
        self.assertTrue(s.writeXml(elem, doc, QgsReadWriteContext()))

        s2 = QgsLayoutGridSettings(l)
        self.assertTrue(s2.readXml(elem.firstChildElement(), doc, QgsReadWriteContext()))

        self.assertEqual(s2.resolution().length(), 5.0)
        self.assertEqual(s2.resolution().units(), QgsUnitTypes.LayoutPoints)
        self.assertEqual(s2.offset().x(), 6.0)
        self.assertEqual(s2.offset().y(), 7.0)
        self.assertEqual(s2.offset().units(), QgsUnitTypes.LayoutPixels)

    def testGettersSetters(self):
        p = QgsProject()
        l = QgsLayout(p)
        s = QgsLayoutGridSettings(l)
        s.setResolution(QgsLayoutMeasurement(5, QgsUnitTypes.LayoutPoints))
        self.assertEqual(s.resolution().length(), 5.0)
        self.assertEqual(s.resolution().units(), QgsUnitTypes.LayoutPoints)

        s.setOffset(QgsLayoutPoint(6, 7, QgsUnitTypes.LayoutPixels))
        self.assertEqual(s.offset().x(), 6.0)
        self.assertEqual(s.offset().y(), 7.0)
        self.assertEqual(s.offset().units(), QgsUnitTypes.LayoutPixels)

        s.setPen(QPen(QColor(255, 0, 255)))
        self.assertEqual(s.pen().color().name(), QColor(255, 0, 255).name())

        s.setStyle(QgsLayoutGridSettings.StyleDots)
        self.assertEqual(s.style(), QgsLayoutGridSettings.StyleDots)