code: public List<GitlabNamespace> getNamespaces() {
          String tailUrl = GitlabNamespace.URL + PARAM_MAX_ITEMS_PER_PAGE;
          return retrieve().getAll(tailUrl, GitlabNamespace[].class);
      }
docs: Get a list of the namespaces of the authenticated user.
  If the user is an administrator, a list of all namespaces in the GitLab instance is shown.
  
  @return A list of gitlab namespace