code: @Override
      public UpdatePullRequestTitleResult updatePullRequestTitle(UpdatePullRequestTitleRequest request) {
          request = beforeClientExecution(request);
          return executeUpdatePullRequestTitle(request);
      }
docs: <p>
  Replaces the title of a pull request.
  </p>
  
  @param updatePullRequestTitleRequest
  @return Result of the UpdatePullRequestTitle operation returned by the service.
  @throws PullRequestDoesNotExistException
  The pull request ID could not be found. Make sure that you have specified the correct repository name and
  pull request ID, and then try again.
  @throws InvalidPullRequestIdException
  The pull request ID is not valid. Make sure that you have provided the full ID and that the pull request
  is in the specified repository, and then try again.
  @throws PullRequestIdRequiredException
  A pull request ID is required, but none was provided.
  @throws TitleRequiredException
  A pull request title is required. It cannot be empty or null.
  @throws InvalidTitleException
  The title of the pull request is not valid. Pull request titles cannot exceed 100 characters in length.
  @throws PullRequestAlreadyClosedException
  The pull request status cannot be updated because it is already closed.
  @sample AWSCodeCommit.UpdatePullRequestTitle
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/codecommit-2015-04-13/UpdatePullRequestTitle"
  target="_top">AWS API Documentation</a>