def METHOD_NAME(request, interface):
  if interface == 'navigator':
    from metadata.catalog.navigator_client import NavigatorApi
    return NavigatorApi(user=request.user)
  elif interface == 'atlas':
    from metadata.catalog.atlas_client import AtlasApi
    return AtlasApi(user=request.user)
  elif interface == 'dummy':
    from metadata.catalog.dummy_client import DummyApi
    return DummyApi(user=request.user)
  else:
    raise PopupException(_('Catalog connector interface not recognized: %s') % interface)