為什么webpack 打包會(huì)有這個(gè)說明，是因?yàn)橛玫搅宋④浀腳_assign函數(shù)，

/*! *****************************************************************************
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Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
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PERFORMANCE OF THIS SOFTWARE.
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var __assign = function() {
    __assign = Object.assign || function __assign(t) {
        for (var s, i = 1, n = arguments.length; i < n; i++) {
            s = arguments[i];
            for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p)) t[p] = s[p];
        }
        return t;
    };
    return __assign.apply(this, arguments);
};

方案一：編譯target不用es5，用es6。

方案二：【推薦】不用 { ...obj } 語法淺拷貝，改用Object.assign({}, obj)淺拷貝（相對__assign效率還高些）
參考： https://blog.csdn.net/kd_2015/article/details/123220478