def setDataAccessor(self, accessor):
""" Sets the DataAccessor from which the boxes are created.
You need to call updateContent() in order to make the changes visible.
"""
if not isinstance(accessor, BasicDataAccessor):
raise TypeError(__name__ + " requires data accessor of type BasicDataAccessor.")
if not isinstance(accessor, RelativeDataAccessor):
raise TypeError(__name__ + " requires data accessor of type RelativeDataAccessor.")
WidgetView.setDataAccessor(self, accessor)
