declare module "v8" {
    interface HeapSpaceInfo {
        space_name: string;
        space_size: number;
        space_used_size: number;
        space_available_size: number;
        physical_space_size: number;
    }

    // ** Signifies if the --zap_code_space option is enabled or not.  1 == enabled, 0 == disabled. */
    type DoesZapCodeSpaceFlag = 0 | 1;

    interface HeapInfo {
        total_heap_size: number;
        total_heap_size_executable: number;
        total_physical_size: number;
        total_available_size: number;
        used_heap_size: number;
        heap_size_limit: number;
        malloced_memory: number;
        peak_malloced_memory: number;
        does_zap_garbage: DoesZapCodeSpaceFlag;
    }

    function getHeapStatistics(): HeapInfo;
    function getHeapSpaceStatistics(): HeapSpaceInfo[];
    function setFlagsFromString(flags: string): void;
}