export type FlowItemId = string & {
    __IS_FLOW_ITEM_ID__: true;
};
export declare const flowItemIdRegExp: RegExp;
export declare function toFlowItemId(itemId: string): FlowItemId;
export declare function isFlowItemId(x: string): x is FlowItemId;
export declare function extractTokenId(x: FlowItemId): number;