Issue #2002946 by mari3.14, malcomio: Rename Views method lgtm() to useStringGroupBy().

core/modules/views/lib/Drupal/views/Plugin/views/display/DisplayPluginBase.php

@@ -916,7 +916,7 @@ public function getHandlers($type) {
    *
    * @param bool $groupable_only
    *   (optional) TRUE to only return an array of field labels from handlers
-   *   that support the use_string_group_by method, defaults to FALSE.
+   *   that support the useStringGroupBy method, defaults to FALSE.
    *
    * @return array
    *   An array of applicable field options, keyed by ID.
@@ -928,7 +928,7 @@ public function getFieldLabels($groupable_only = FALSE) {
     }
 
     foreach ($this->getHandlers('field') as $id => $handler) {
-      if ($groupable_only && !$handler->use_string_group_by()) {
+      if ($groupable_only && !$handler->useStringGroupBy()) {
         // Continue to next handler if it's not groupable.
         continue;
       }

core/modules/views/lib/Drupal/views/Plugin/views/field/FieldPluginBase.php

@@ -402,7 +402,7 @@ function get_value($values, $field = NULL) {
    * @return bool
    *  TRUE if this field handler is groupable, otherwise FALSE.
    */
-  function use_string_group_by() {
+  public function useStringGroupBy() {
     return TRUE;
   }
 
@@ -1672,3 +1672,4 @@ public static function trimText($alter, $value) {
 /**
  * @}
  */
+