'Add a new scale handle to the ROI. Dragging a scale handle allows the
user to change the height and/or width of the ROI.
**Arguments**
pos                 (length-2 sequence) The position of the handle
relative to the shape of the ROI. A value of (0,0)
indicates the origin, whereas (1, 1) indicates the
upper-right corner, regardless of the ROI\'s size.
center              (length-2 sequence) The center point around which
scaling takes place. If the center point has the
same x or y value as the handle position, then
scaling will be disabled for that axis.
item                The Handle instance to add. If None, a new handle
will be created.
name                The name of this handle (optional). Handles are
identified by name when calling
getLocalHandlePositions and getSceneHandlePositions.'

def addScaleHandle(self, pos, center, axes=None, item=None, name=None, lockAspect=False, index=None):

    pos = Point(pos)
    center = Point(center)
    info = {'name': name, 'type': 's', 'center': center, 'pos': pos, 'item': item, 'lockAspect': lockAspect}
    if (pos.x() == center.x()):
        info['xoff'] = True
    if (pos.y() == center.y()):
        info['yoff'] = True
    return self.addHandle(info, index=index)
