'Call setExportMode(export, opts) on all items that will
be painted during the export. This informs the item
that it is about to be painted for export, allowing it to
alter its appearance temporarily
*export*  - bool; must be True before exporting and False afterward
*opts*    - dict; common parameters are \'antialias\' and \'background\''

def setExportMode(self, export, opts=None):

    if (opts is None):
        opts = {}
    for item in self.getPaintItems():
        if hasattr(item, 'setExportMode'):
            item.setExportMode(export, opts)
