Truncate help add method and suffix (#19425)

#19424

framework/helpers/BaseStringHelper.php

@@ -109,8 +109,8 @@ public static function dirname($path)
      * Truncates a string to the number of characters specified.
      *
      * In order to truncate for an exact length, the $suffix char length must be counted towards the $length. For example
-     * to have a string which is exactly 255 long with $suffix `...` then `StringHelper::($string, 252)` must be used to ensure
-     * you have 255 long string afterwards.
+     * to have a string which is exactly 255 long with $suffix `...` of 3 chars, then `StringHelper::truncate($string, 252, '...')` 
+     * must be used to ensure you have 255 long string afterwards.
      *
      * @param string $string The string to truncate.
      * @param int $length How many characters from original string to include into truncated string.