This class implements those common utility methods from the GameMap
interface that can be implemented without needing to know the
underlying representation.
This property encapsulates an object's bitmap & category, and
updates the bitmap number (a reference into the bitmap database)
every time either is changed.
Provides the "autobag" command, which lets you set up and administer
rules (similar to mail-filtering rules) that automatically place
objects in bags according to user-specified criteria.
Encapsulates a single Autobag rule, including the rule name,
the conditions for activating this rule, and the bag(s) to put
the items in when the rule is activated.