Issue #2411323 by tadityar: FieldStorageConfig::isRequired should not exist

core/modules/field/src/Entity/FieldStorageConfig.php

@@ -588,13 +588,6 @@ public function getCardinality() {
     return $this->cardinality;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function isRequired() {
-    return FALSE;
-  }
-
   /**
    * {@inheritdoc}
    */