Service interface which can be implemented to define an algorithm used to pick
resources to be merged. For each picker service, a separate ResourceProviderFactory
will be exposed at the MERGE_ROOT of the picker.
Service property name identifying the root path for the merged resources.
By convention, starts, with /mnt, although this is by no means required.
The value of this service property must be of type String and must not end
in a slash.
Service property name specifying whether the parent hierarchy is
traversed to check for hiding properties. If not specified this
property defaults to false. The value of this
property must be of type Boolean.
Method invoked by the MergingResourceProvider to identify the resources to be merged for a given
relative path. The resources returned may be either resources returned from the ResourceResolver
directory or an instance of NonExistingResource.
resolver - the ResourceResolver
relativePath - the path relative to the merge root
relatedResource - an optional resource which is related to the given path (parent or child)