Method getOrCreate

packages/client-common/src/Cache.ts:15–23

(key: K, create: () => V)

  }

  getOrCreate(key: K, create: () => V): V {
    const cached = this._map.get(key)
    if (cached) {
      return cached.value
    }
    const value = create()
    this.set(key, value)
    return value
  }
}