/**
     * Cache control request directives that uses the cache only, even if the cached response is
     * stale. If the response isn't available in the cache or requires server validation, the call
     * will fail with a `504 Unsatisfiable Request`.
     */
    @JvmField
    val FORCE_CACHE = commonForceCache()

    /**
     * Returns the cache directives of [headers]. This honors both Cache-Control and Pragma headers