code: function(userId) {
          // send the request to all of our own devices, and the
          // original sending device if it wasn't us.
          const wireContent = this.getWireContent();
          const recipients = [{
              userId, deviceId: '*',
          }];
          const sender = this.getSender();
          if (sender !== userId) {
              recipients.push({
                  userId: sender, deviceId: wireContent.device_id,
              });
          }
          return recipients;
      }
docs: Calculate the recipients for keyshare requests.
  
  @param {string} userId the user who received this event.
  
  @returns {Array} array of recipients