def copy
    copy = super
    #Make deep copy of each behavior.
    copy.instance_eval {@behaviors = []}
    self.behaviors.each {|behavior| copy.add_behavior(behavior.copy)}
    copy
  end
def copy
    copy = super
    #Make deep copy of each behavior.
    copy.instance_eval {@behaviors = []}
    self.behaviors.each {|behavior| copy.add_behavior(behavior.copy)}
    copy
  end
Make a deep copy.