/**
 * Returns if the given function is a model flow or not.
 *
 * @param fn Function to check.
 * @returns
 */
export declare function isModelFlow(fn: any): any;
/**
 * Decorator that turns a function generator into a model flow.
 *
 * @param target
 * @param propertyKey
 * @param [baseDescriptor]
 * @returns
 */
export declare function modelFlow(target: any, propertyKey: string, baseDescriptor?: PropertyDescriptor): void;
/**
 * Tricks the TS compiler into thinking that a model flow generator function can be awaited
 * (is a promise).
 *
 * @typeparam A Function arguments.
 * @typeparam R Return value.
 * @param fn Flow function.
 * @returns
 */
export declare function _async<A extends any[], R>(fn: (...args: A) => Generator<any, R, any>): (...args: A) => Promise<R>;
/**
 * Makes a promise a flow, so it can be awaited with yield*.
 *
 * @typeparam T Promise return type.
 * @param promise Promise.
 * @returns
 */
export declare function _await<T>(promise: Promise<T>): Generator<Promise<T>, T, unknown>;