/**
 * @name isFunction
 * @summary Tests for a `function`.
 * @description
 * Checks to see if the input value is a JavaScript function.
 * @example
 * <BR>
 *
 * ```javascript
 * import { isFunction } from '@polkadot/util';
 *
 * isFunction(() => false); // => true
 * ```
 */
export default function isFunction(value: any): value is Function;
