private Single<PullRequest> getPullRequest(String login, String name,
                                                         int issueNumber) {
        return ServiceGenerator.createService(context, PullRequestService.class)
                .getPullRequest(login, name, issueNumber)
                .map(Response::body);
    }
Fetches all comments for a given issue.

@param login
@param name
@param issue
@return {@link Single}
app/src/main/java/com/github/pockethub/android/core/issue/RefreshIssueTask.java