sudo functionality is inconvenient

[slonopotamus]

Currently, GitLabApi mutates itself when caller wants to use sudo functionality, but.

1. This cannot be safely used in multithreaded environment
2. GitLabApi doesn't provide any means to clone its instance (so cloned one would be mutated for sudo and original one kept untouched)

Ideally, sudo should be configurable per-request, giving the same flexibility that is available if user doesn't use gitlab4j-api at all and directly issues HTTP requests to GitLab, without modifying GitLabApi instance.

[gmessner]

I have added the ability to fetch the authToken and tokenType (#119) (and other properties) so you can now create a copy of an GitLabApi instance. I've also created duplicate() method that will duplicate an instance of GitLabApi. I would recommend using this duplicate() method to create a copy of a GitLabApi instance.

It would be difficult to add per request capability for sudo, however, it can be turned on and off before and after an API call:

gitLabApi.sudo(TEST_SUDO_AS_USERNAME);
User user = gitLabApi.getUserApi().getCurrentUser();
gitLabApi.unsudo();

I would recommend using ThreadLocal and create a GitLabApi instance for each thread if you must have multiple threads going against the API at the same time.

Another option would be to create a new instance of GitLabApi for each invocation. I've modified the GitLabApi class to use lazy instantiation of the sub APIs to make it a bit more lightweight.

These mods are available in release 4.7.9.