def METHOD_NAME(cls):
    # main project group
    cls.project_group = CoreGroup(name='Group1', title='Group1', header_logo_img='',
                                  srid=G3WSpatialRefSys.objects.get(auth_srid=4326))
    cls.project_group.save()
    qgis_project_file = File(open('{}{}{}'.format(CURRENT_PATH, TEST_BASE_PATH, QGS_FILE), 'r'))
    cls.project = QgisProject(qgis_project_file)
    cls.project.title = 'A project'
    cls.project.group = cls.project_group
    cls.project.save()
    # make a fake vector postgis layer
    # ===================================
    fake_layer1, created = Layer.objects.get_or_create(
        name='fakelayer',
        title='fakelayer',
        origname='fakelayer',
        qgs_layer_id='fakelayer_23456',
        project=cls.project.instance,
        layer_type='postgres',
        datasource="dbname='geo_demo' host=localhost port=5432 user='postgres' password='postgres' sslmode=disable "
                   "key='id' srid=3003 type=Polygon checkPrimaryKeyUnicity='1' "
                   "table=\"casentino\".\"piano_parco\" (geom) sql="
    )
    fake_layer2, created = Layer.objects.get_or_create(
        name='fakelayer2',
        title='fakelayer2',
        origname='fakelayer2',
        qgs_layer_id='fakelayer2_23456',
        project=cls.project.instance,
        layer_type='postgres',
        datasource="dbname='geo_demo' host=localhost port=5432 user='postgres2' password='HHHHH' sslmode=disable "
                   "key='id' srid=3003 type=Polygon checkPrimaryKeyUnicity='1' "
                   "table=\"casentino\".\"piano_parco\" (geom) sql="
    )
    # change datasource
    fake_layer3, created = Layer.objects.get_or_create(
        name='fakelayer3',
        title='fakelayer3',
        origname='fakelayer3',
        qgs_layer_id='fakelayer3_23456',
        project=cls.project.instance,
        layer_type='postgres',
        datasource="dbname='geo_demo' host=localhost port=5432 user='postgres1' password='XXXX' sslmode=disable "
                   "key='id' srid=3003 type=Polygon checkPrimaryKeyUnicity='1' "
                   "table=\"casentino\".\"piano_parco\" (geom) sql="
    )
    layers = cls.project.instance.layer_set.all()
    for l in layers:
        if l.qgs_layer_id == 'fakelayer_23456':
            cls.fake_layer1 = l
        if l.qgs_layer_id == 'fakelayer2_23456':
            cls.fake_layer2 = l
        if l.qgs_layer_id == 'fakelayer3_23456':
            cls.fake_layer3 = l
    qgis_project_file = File(open('{}{}{}'.format(CURRENT_PATH, TEST_BASE_PATH, QGS310_FILE), 'r'))
    cls.project310 = QgisProject(qgis_project_file)
    cls.project310.title = 'A project QGIS 3.10'
    cls.project310.group = cls.project_group
    cls.project310.save()