Default Reviewers for a branch creating Pull-Request

While creating a pull-request through commandline, I want to add 'default' reviewers for a branch. I want to know if Bitbucket has already assigned default reviewers for a branch? If this feature is available, I would be able to use the same script for every branch in different repositories.

For instance:
The default reviewers could be members of all the branches connected with the master except the one making the pull request.