Motivation:
A BOM should only expose dependency management for the artifacts that the project produces (so in this case, netty artifacts). It should not have an opinion about third party dependencies (otherwise including that BOM in a project potentially overrides decisions that were made about them).
Modifications:
Stop inheriting from netty-parent and explicitly set the versions for the artifacts.
Result:
Valid BOM.
Motivation:
Projects may import multiple libraries which use different versions of Netty.
Modifications:
Add 'netty-bom' meta-project that contains the other projects in a dependencyManagement section.
Result:
Developers can import the BOM to enforce specific version of Netty.