Collective - this is an object that can be used to refer to a group of other (usually equivalent) objects collectively. In most cases, this object will be a separate game object that contains or can contain the individuals: a bag of marbles can be a collective for the marbles, or a book of matches can be a collective for the matchsticks.

A collective object is usually given the same plural vocabulary as its individuals. When we use that plural vocabulary, we will filter for or against the collective, as determined by the noun phrase production, when the player uses the collective term.

This is a mix-in class, intended to be used along with other (usually Thing-derived) superclasses.

class Collective :   object