code: public Pager<Namespace> getNamespaces(int itemsPerPage) throws GitLabApiException {
          return (new Pager<Namespace>(this, Namespace.class, itemsPerPage, null, "namespaces"));
      }
docs: Get a Pager of the namespaces of the authenticated user. If the user is an administrator,
  a Pager of all namespaces in the GitLab instance is returned.
  
  <pre><code>GitLab Endpoint: GET /namespaces</code></pre>
  
  @param itemsPerPage the number of Project instances that will be fetched per page
  @return a Pager of Namespace instances
  @throws GitLabApiException if any exception occurs