Fix ECS

Author: BenMorel

src/NameMapper/CamelCaseToSnakeCaseMapper.php

@@ -7,6 +7,7 @@
 use Brick\JsonMapper\NameMapper;
 use Override;
 
+use function assert;
 use function preg_replace_callback;
 use function strtolower;
 

src/NameMapper/SnakeCaseToCamelCaseMapper.php

@@ -7,6 +7,7 @@
 use Brick\JsonMapper\NameMapper;
 use Override;
 
+use function assert;
 use function preg_replace_callback;
 use function strtoupper;
 

src/Reflection/Reflector.php

@@ -23,6 +23,7 @@
 use UnitEnum;
 
 use function array_map;
+use function assert;
 use function count;
 use function implode;
 use function in_array;