code: function isError(value) {
    var tag = toString.call(value);
    switch (tag) {
      case '[object Error]': return true;
      case '[object Exception]': return true;
      case '[object DOMException]': return true;
      default: return value instanceof Error;
    }
  }
docs: @description
  Determines if a reference is an `Error`.
  Loosely based on https://www.npmjs.com/package/iserror
  
  @param {*} value Reference to check.
  @returns {boolean} True if `value` is an `Error`.