Because the property `serviceMap` can be null the function `array_key_exists` raise a warning in class [`ContainerModelLayerPooler`](https://github.com/pomm-project/pomm-bundle/blob/2.3.0/sources/lib/Model/ContainerModelLayerPooler.php#L47). We are using PommBundle 2.3.0
Because the property
serviceMapcan be null the functionarray_key_existsraise a warning in classContainerModelLayerPooler.We are using PommBundle 2.3.0