def mapper_configured(self, mapper, class_):
"""Called when the mapper for the class is fully configured.
- This event is the latest phase of mapper construction.
- The mapper should be in its final state.
+ This event is the latest phase of mapper construction, and
+ is invoked when the mapped classes are first used, so that relationships
+ between mappers can be resolved. When the event is called,
+ the mapper should be in its final state.
+
+ While the configuration event normally occurs automatically,
+ it can be forced to occur ahead of time, in the case where the event
+ is needed before any actual mapper usage, by using the
+ :func:`.configure_mappers` function.
+
:param mapper: the :class:`.Mapper` which is the target
of this event.