#  Copyright (c) 2007, Enthought, Inc.
#  License: BSD Style.


# add_class_trait.py --- Example of mutually-referring classes
#                        using add_class_trait()


#--[Imports]--------------------------------------------------------------------

from traits.api import HasTraits, Instance

#--[Code]-----------------------------------------------------------------------

# Defining mutually-referring classes using add_class_trait()

class Chicken ( HasTraits ):

    pass


class Egg ( HasTraits ):

    created_by = Instance( Chicken )

# Now that 'Egg' is defined, we can add the 'hatched_from' trait to
# solve the mutual-reference problem...

Chicken.add_class_trait( 'hatched_from', Instance( Egg ) )