code: public Project transferProject(Object projectIdOrPath, String namespace) throws GitLabApiException {
          GitLabApiForm formData = new GitLabApiForm().withParam("namespace", namespace, true);
          Response response = put(Response.Status.OK, formData.asMap(), "projects", getProjectIdOrPath(projectIdOrPath), "transfer");
          return (response.readEntity(Project.class));
      }
docs: Transfer a project to a new namespace.  This was added in GitLab 11.1
  
  <pre><code>PUT /projects/:id/transfer.</code></pre>
  
  @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
  @param namespace the namespace to transfer the project to
  @return the updated Project
  @throws GitLabApiException if any exception occurs