Configuration data key, used for config.lookup() et al

Configuration keys may be polymorphic at registration or lookup time. IOW, when looking up a configuration key, you can search multiple values that would imply the key being looked for. And, when registering a value for a configuration key, the key can supply alternate keys that it should be registered under. Thus, an IConfigKey is never itself directly used as a key, only the values supplied by its registrationKeys() and lookupKeys() methods are used. (However, those values must themselves be adaptable to IConfigKey, and they must be usable as dictionary keys.)

lookupKeys ()

parentKeys ()

registrationKeys ( depth=0 )