Protects a specified branch through push and merge rules in an existing GitLab project using a user's private token (obtained in GitLab under the intended user's 'Settings' => 'Account'). The branch to be protected is found through providing the projects path (which is the project name provided in the URL - not necessarily the same as the readable name) and the branch name. Once the project is found, the push and merge capabilities can be enforced in the following 3 levels: 'none' means no one can modify the branch while 'masters'/'developers' map to the 'Master'/'Developer' GitLab Member permissions for the specified project. If 'Allowed to push' or 'Allowed to merge' is not provided, it will either stay the same as before if edited an already protected branch or default to 'masters' if this is a new protected branch. An empty result set will be returned on a successful branch protection attempt.