[BitBucket Cloud] Unable to obtain commits of a PR

There is an API available to obtain commits in a PR https://developer.atlassian.com/cloud/bitbucket/rest/api-group-pullrequests/#api-repositories-workspace-repo-slug-pullrequests-pull-request-id-commits-get

But there is no corresponding function in the PullRequest object. 

I want to obtain the list of commits in a PR

I am using the latest version of the library