code: function stackSet(key, value) {
    var data = this.__data__;
    if (data instanceof _ListCache) {
      var pairs = data.__data__;
      if (!_Map || (pairs.length < LARGE_ARRAY_SIZE - 1)) {
        pairs.push([key, value]);
        this.size = ++data.size;
        return this;
      }
      data = this.__data__ = new _MapCache(pairs);
    }
    data.set(key, value);
    this.size = data.size;
    return this;
  }
docs: Sets the stack `key` to `value`.
  
  @private
  @name set
  @memberOf Stack
  @param {string} key The key of the value to set.
  @param {*} value The value to set.
  @returns {Object} Returns the stack cache instance.