Issue #3154914 by ju.vanderw: Fix grammar usage of singular/plural

   * signature: f($user, $node, $foo) returning either values or labels

   * like "user: Dries, node: First post, foo: bar"

   *

   * The tests shuffle the parameters around an checks if the right thing is

   * The test shuffles the parameters around and checks if the right thing is

   * happening.

   */

  public function testUpcasting() {

          // Grouped exposed filters have their own forms.

          // Instead of render the standard exposed form, a new Select or

          // Radio form field is rendered with the available groups.

          // When an user choose an option the selected value is split

          // When an user chooses an option the selected value is split

          // into the operator and value that the item represents.

          if ($handler->isAGroup()) {

            $handler->groupForm($form, $form_state);