getBySteam64Id(steam64Id) {
        const idString = steam64Id instanceof Long ? steam64Id.toString() : steam64Id;
        const entityIndex = this._steam64IdToEntity.get(idString);
        if (entityIndex === undefined)
            return null;
        return this.entities.get(entityIndex);
    }
Returns the entity that belongs to the player with a given 64-bit Steam ID.
@param {Long|string} steam64Id - 64-bit Steam ID
@returns {Player|null} Entity referenced by the Steam ID. `null` if no matching player.