kotlin add value to MutableLiveData

private val mIssuePosts = ArrayList<IssuePost>()
private val mIssuePostLiveData = MutableLiveData<List<IssuePost>>()

fun addIssuePost(issuePost: IssuePost) {
   mIssuePosts.add(issuePost)
   mIssuePostLiveData.value = mIssuePosts
}