+ /* The base class recently acquired Game.players which works like
+ * Empires.spectators, (and meanwhile the Empires._players
+ * functionality could perhaps be reworked into
+ * Game.players[].team). Until we do that rework, lets use
+ * .registered_players as the getter for the Empires-specific
+ * ._players property to avoid mixing it up with the distinct
+ * Game.players property. */
+ get registered_players() {