materio-base-d7/sites/all/modules/contrib/fields/field_group/tests/field_group_test.module

<?php

/**
 * @file
 * Fieldgroup test module.
 */

/**
 * Implements hook_field_access().
 */
function field_group_test_field_access($op, $field, $entity_type, $entity, $account) {
  // Set access to false for field_no_access.
  if ($op == 'view' && $field['field_name'] == 'field_no_access') {
    return FALSE;
  }
}