const lairId = cache.inHeap('lair:' + this.id, 150_000, () => {
        // @todo Could use old data and just check if object still exits.
        // Check if there is a lair nearby.
        const structures = this.pos.findInRange(FIND_STRUCTURES, 10, {
            filter: structure => structure.structureType === STRUCTURE_KEEPER_LAIR,