Tests hiding the view modes fieldset when there's only one available.
function testSingleViewMode() {
$this
->drupalGet('admin/structure/taxonomy/manage/' . $this->vocabulary . '/display');
$this
->assertNoText('Use custom display settings for the following view modes', 'Custom display settings fieldset found.');
// This may not trigger a notice when 'view_modes_custom' isn't available.
$this
->drupalPost('admin/structure/taxonomy/manage/' . $this->vocabulary . '/display', array(), t('Save'));
}