getDialogId(session) {
    if (!session.dialogStack) {
      return '';
    }
    const stack = session.dialogStack();
    for (let i = 0; i < stack.length; i += 1) {
      const dialogId = stack[i];
      if (dialogId.startsWith('*:')) {
        return dialogId.substring(2);
      }
    }
    return '';
  }
Gets the last developer (not framework) dialogId on the stack.
@param {Object} session Microsoft bot framework session.
@returns {string} Last dialog id.