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- 'use strict';
- var _require = require('../helpers/is'),
- isFunction = _require.isFunction;
- module.exports = function average(key) {
- if (key === undefined) {
- return this.sum() / this.items.length;
- }
- if (isFunction(key)) {
- return new this.constructor(this.items).sum(key) / this.items.length;
- }
- return new this.constructor(this.items).pluck(key).sum() / this.items.length;
- };
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