608   QDomElement extentElem = doc.createElement( QStringLiteral( "Extent" ) );  in writePropertiesToElement()  local
609   extentElem.setAttribute( QStringLiteral( "xmin" ), qgsDoubleToString( mExtent.xMinimum() ) );  in writePropertiesToElement()
610   extentElem.setAttribute( QStringLiteral( "xmax" ), qgsDoubleToString( mExtent.xMaximum() ) );  in writePropertiesToElement()
611   extentElem.setAttribute( QStringLiteral( "ymin" ), qgsDoubleToString( mExtent.yMinimum() ) );  in writePropertiesToElement()
612   extentElem.setAttribute( QStringLiteral( "ymax" ), qgsDoubleToString( mExtent.yMaximum() ) );  in writePropertiesToElement()
613   mapElem.appendChild( extentElem );  in writePropertiesToElement()
720     QDomElement extentElem = extentNodeList.at( 0 ).toElement();  in readPropertiesFromElement()  local
722     xmin = extentElem.attribute( QStringLiteral( "xmin" ) ).toDouble();  in readPropertiesFromElement()
723     xmax = extentElem.attribute( QStringLiteral( "xmax" ) ).toDouble();  in readPropertiesFromElement()
724     ymin = extentElem.attribute( QStringLiteral( "ymin" ) ).toDouble();  in readPropertiesFromElement()
725     ymax = extentElem.attribute( QStringLiteral( "ymax" ) ).toDouble();  in readPropertiesFromElement()