|  | var baseFlatten = require('./_baseFlatten'), | 
|  | map = require('./map'); | 
|  |  | 
|  | /** Used as references for various `Number` constants. */ | 
|  | var INFINITY = 1 / 0; | 
|  |  | 
|  | /** | 
|  | * This method is like `_.flatMap` except that it recursively flattens the | 
|  | * mapped results. | 
|  | * | 
|  | * @static | 
|  | * @memberOf _ | 
|  | * @since 4.7.0 | 
|  | * @category Collection | 
|  | * @param {Array|Object} collection The collection to iterate over. | 
|  | * @param {Function} [iteratee=_.identity] The function invoked per iteration. | 
|  | * @returns {Array} Returns the new flattened array. | 
|  | * @example | 
|  | * | 
|  | * function duplicate(n) { | 
|  | *   return [[[n, n]]]; | 
|  | * } | 
|  | * | 
|  | * _.flatMapDeep([1, 2], duplicate); | 
|  | * // => [1, 1, 2, 2] | 
|  | */ | 
|  | function flatMapDeep(collection, iteratee) { | 
|  | return baseFlatten(map(collection, iteratee), INFINITY); | 
|  | } | 
|  |  | 
|  | module.exports = flatMapDeep; |