/**
 * Implements hook_entity_delete().
 */
function {{ machine_name }}_entity_delete($entity, $type) {
  // Delete the entity's entry from a fictional table of all entities.
  $info = entity_get_info($type);
  list($id) = entity_extract_ids($type, $entity);
  db_delete('example_entity')
    ->condition('type', $type)
    ->condition('id', $id)
    ->execute();
}