public static function findValuesRemovedFromEnums(
        Schema $oldSchema,
        Schema $newSchema
    ) {
        $oldTypeMap = $oldSchema->getTypeMap();
        $newTypeMap = $newSchema->getTypeMap();

        $valuesRemovedFromEnums = [];
        foreach ($oldTypeMap as $typeName => $oldType) {
            $newType = $newTypeMap[$typeName] ?? null;
            if (! ($oldType instanceof EnumType) || ! ($newType instanceof EnumType)) {
                continue;
            }
            $valuesInNewEnum = [];
            foreach ($newType->getValues() as $value) {
                $valuesInNewEnum[$value->name] = true;
            }
            foreach ($oldType->getValues() as $value) {
                if (isset($valuesInNewEnum[$value->name])) {
                    continue;
                }

                $valuesRemovedFromEnums[] = [
                    'type'        => self::BREAKING_CHANGE_VALUE_REMOVED_FROM_ENUM,
                    'description' => sprintf('%s was removed from enum type %s.', $value->name, $typeName),
                ];
            }
        }

        return $valuesRemovedFromEnums;
    }