A population has a name, a position in the population tree, and a number of entities. Derived versions include a PopulationBuilder for constructing a number of similar entities (maybe in a 2D layer, or randomly distributed in some volume) and a PopulationView which provides a view of an existing population based on some entity characteristic (e.g. all the entities in a given region, or a grid based decomposition of a volume of entities).
Population( String name, PopulationNode parent ) int getId() int getNumEnts() int getIndex( EntityID eid ) boolean isMember( Entity e ) Vector getMemberList()