code: @POST
      @Consumes(MediaType.APPLICATION_JSON)
      @Produces(MediaType.APPLICATION_JSON)
      @Description("Creates a new namepsace.")
      public NamespaceDto createNamespace(@Context HttpServletRequest req, NamespaceDto namespaceDto) {
          if (namespaceDto == null) {
              throw new WebApplicationException("Null namespace object cannot be created.", Status.BAD_REQUEST);
          }
  
          PrincipalUser remoteUser = validateAndGetOwner(req, null);
          Set<PrincipalUser> users = _getPrincipalUserByUserName(namespaceDto.getUsernames());
          Namespace namespace = new Namespace(remoteUser, namespaceDto.getQualifier(), remoteUser, users);
  
          return NamespaceDto.transformToDto(_namespaceService.createNamespace(namespace));
      }
docs: Creates a new namespace.
  
  
  @param   req           The HTTP request.
  @param   namespaceDto  The namespace to create.
  
  @return  The updated namespace DTO for the created namespace.
  
  @throws  WebApplicationException  If an error occurs.