Hi,
Currently the implementation of #children in MooseEntity is really fragile. In the current implementation, we select all the selectors matching "all*s" and we merge the results of these methods.
This is fragile because we could have #allContainerFiles that would not return children. Also it is possible that there is no method matching this pattern for some children.
In the meanwhile, Anne, Jean-Christophe and Vincent worked in the usage of the mse properties in order to build more generic algos. There is currently a #childrenEntities and a #parentEntities methods to get the children/parents based on the meta-model of the language. I think this is now stable.
I will deprecate #childrenEntities and #parentEntities and rename them #children and #parents now.
So, no need to implement some #children methods anymore :)