code: function stackDelete(key) {
      var data = this.__data__,
        result = data['delete'](key);
  
      this.size = data.size;
      return result;
    }
docs: Removes `key` and its value from the stack.
  
  @private
  @name delete
  @memberOf Stack
  @param {string} key The key of the value to remove.
  @returns {boolean} Returns `true` if the entry was removed, else `false`.