The current ResourceResolver#map methods return a single "path mapped from the (resource) path". However, it is possible than a given path can be mapped to multiple others while using features such as sling:alias and sling:vanityUrl.
In order to support that scenario, it is require to implement new maps method for ResourceResolver which returns a collection of "resolved path". This collection must contain the resources mapped through /etc/map, sling:alias and sling:vanityUrl.
The current API suggests to implement a second method to be consistent/symmetric with the existing map operations
@Nonnull java.util.Collection<java.lang.String> maps(@Nonnull java.lang.String resourcePath)
@Nonnull java.util.Collection<java.lang.String> maps(@Nonnull javax.servlet.http.HttpServletRequest request, @Nonnull java.lang.String resourcePath)